JP3509258B2 - Driver circuit having transmission line loss compensation means - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system including a driver circuit for transmitting a signal using a transmission line, and more particularly to a driver circuit capable of compensating for a loss in the transmission line.

[0002]

2. Description of the Related Art Conventionally, loss compensation in a transmission line has been performed by using a filter circuit composed of a coil or a capacitance so that the frequency characteristic of an amplifier circuit is opposite to the loss characteristic of the transmission line. . For example, as disclosed in Japanese Utility Model Application Laid-Open No. 5-87750, a peaking coil is used to increase the amplification factor at a high frequency to compensate for a high-frequency component that is attenuated due to a loss in a transmission line.

[0003]

In a driver circuit provided with such a conventional loss compensating means, since a filter circuit composed of a coil or a capacitor is used, the frequency characteristic of the driver circuit is adjusted according to the loss of one transmission line. However, it was difficult to use the driver circuit for another transmission line. Further, when a coil is used for the filter circuit, there is a problem that it is difficult to integrate the driver circuit into an integrated circuit.

An object of the present invention is to provide a driver circuit and a transmission line loss compensation method that can easily cope with an arbitrary transmission line.

A further object of the present invention is to provide a driver circuit and a transmission line loss compensation method suitable for integration into a circuit without using a filter circuit having a coil.

[0006]

In the driver circuit for amplifying a signal to be transmitted and outputting it to a transmission line, a storage means for storing a pulse width and an amplitude of a pulse having a predetermined waveform shape is provided. One or more pulse generating means for generating a pulse having a pulse width and an amplitude stored in the storage means at the rising and falling edges of the signal to be transmitted; the signal to be transmitted; This can be achieved by a driver circuit characterized in that it has addition means for adding pulses output from one or more pulse wave generators, and amplification means for amplifying the output of the adder.

As the pulse having a predetermined waveform generated by the pulse generating means of the driver circuit, for example, a square wave pulse or a triangular wave pulse is used.

[0008]

In the driver circuit of the present invention, in order to compensate the rising and falling portions of the waveform of the signal to be transmitted, in which the high-frequency component is attenuated due to the loss in the transmission line, a predetermined pulse width and One or more pulses having a waveform shape such as a square wave or a triangular wave having an amplitude are added to the signal waveform in synchronization with switching between the high level (Hi) and the low level (Low) of the signal waveform.

In the present invention, the storage means stores the pulse width and amplitude of one or more pulses to be added to the signal waveform, which is preset according to the loss characteristic of the transmission line used. Further, the one or more pulse generation means changes the pulse width and amplitude of the generated pulse according to the pulse width and amplitude stored in the storage means. Therefore, by changing the data stored in the storage means, it is possible to perform loss compensation on any transmission line.

Further, the driver circuit of the present invention does not use a filter circuit having a coil unlike the conventional driver circuit for compensating for the loss of the transmission line, and is therefore suitable for integration into an integrated circuit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a driver circuit having a transmission line loss compensating means to which the present invention is applied will be described below with reference to the drawings.

An embodiment of a driver circuit having a transmission line loss compensating means according to the present invention will be described with reference to FIGS.

The driver circuit 8 of this embodiment is, for example, as shown in FIG.
As shown in FIG. 2, a signal generator 1 for generating a signal to be transmitted via the transmission line 9 and a register 2 for storing pulse width data and amplitude data of a square wave pulse used for loss compensation in the transmission line 9. And square wave generators 3, 4, 5, ... Which generate a square wave according to the pulse width data and the amplitude data stored in the register 2.

In this embodiment, the output 1a of the signal generator 1, the output 3a of the square wave generator 3, and the square wave generator 4 are further provided.
Of the square wave generator 5 and an adder 6 for amplifying the output 6a of the adder 6 and an amplifier circuit 7 for amplifying the output 6a of the adder 6.

A method of compensating for the transmission line loss performed by the driver circuit 8 of this embodiment will be described with reference to the waveform diagrams of FIGS. In the following, a case where the signal to be transmitted is a digital signal and the number of square wave generators is 3 will be described.

Waveform 10 (FIG. 2 (a)) shows the signal generator 1
3 shows a waveform of a part of the signal generated in 1. at the rising edge. In the case of a driver circuit that does not perform loss compensation on the transmission line, the signal having such a waveform 10 is supplied as it is to the transmission line 9 via the amplifier circuit 7.

Then, due to the loss of the skin effect in the transmission line 9, the high frequency component at the rising portion is attenuated, and at the transmission line end 9a, as shown by the waveform 11 (FIG. 2B),
The waveform is dull. Such a transmission line loss becomes more significant as the frequency of the signal to be transmitted becomes higher. For example, in the case of a signal of 100 MHz or more, even the transmission line 9 of about 50 cm has a large loss due to the skin effect or the like.

In the present embodiment, for example, in order to compensate for the loss in the transmission line 9 of 50 cm or more in the frequency band of 100 MHz or more, or the transmission line 9 of several m or more in the lower frequency band, FIG. ), Waveform 10 and waveform 11
Square wave 12, square wave 13, and square wave 14 with pulse width and amplitude corresponding to the magnitude and shape of the difference between
Is added to the waveform to be transmitted (hereinafter referred to as the original waveform) 10.

Here, the pulse width and amplitude of each of the square waves 12, 13 and 14 are, for example, the difference between the waveform formed by adding these three square waves to the original waveform 10 and the waveform 11. It is determined to be the minimum or less than or equal to a predetermined threshold. Further, considering the characteristics of the loss in the transmission line handled in this embodiment, as shown in FIG.
By determining the pulse width and amplitude of each square wave to be different from each other, the difference from the waveform 11 can be made smaller.

That is, the waveform of the output 7a of the amplifier circuit 7 is a square wave having a pulse width and an amplitude different from each other, which are obtained in advance, like a waveform 15 (a thick line portion in FIG. 2D). 12, square wave 13 and square wave 14
Is added to the original waveform 10 at the same timing as the switching of the waveform to the high level (Hi) and the low level (Low).

When the waveform 15 formed as described above is supplied to the transmission line 9 and suffers a loss in the transmission line 9, FIG.
The waveform 16 is as shown in (e).

Therefore, according to this embodiment, a waveform 16 closer to the original waveform 10 can be obtained as compared with the waveform 11 at the transmission line end 9a when the loss compensation in the transmission line is not performed. It becomes possible to compensate the transmission line loss.

In the above, the waveform at the rising edge of the signal as shown in FIG. 2 has been described, but FIGS. 3 (a) to 3 (e)
As shown in, even when the signal falls, the same thing can be said. Here, the description of the operation of the present embodiment at the time of the falling edge of the signal is the same as that at the time of the above-mentioned rising edge, and is omitted. In addition, in FIG. 3, as in FIG.
Is the original waveform, 11 is the waveform that has suffered loss in the transmission line 9,
Reference numeral 15 is an output waveform of the driver circuit 8 in this embodiment, and 1
Reference numeral 6 shows a waveform when the waveform 15 receives a loss due to the transmission line 9.

In the driver circuit 8 of this embodiment, as described above, the difference between the original waveform 10 and the waveform 11 that has suffered a loss in a specific transmission line 9 is dealt with (see FIG. 2).
(C) and FIG. 3 (c)), the pulse width and amplitude of each square wave are obtained in advance as data and stored in the register 2.

Further, according to the pulse width data and the amplitude data stored in the register 2, the square wave generator 3, the square wave generator 4 and the square wave generator 5 generate a square wave 3a, a square wave 4a and a square wave 5a. Then, the adder 6 adds the output 5a of the signal generator 5 and the output 6a of the adder is amplified by the amplifier circuit 7 to obtain a waveform 15.

Here, the square wave generator in this embodiment is capable of varying the pulse width and the amplitude of the generated square wave. Therefore, when the transmission line 9 is changed, the data stored in the register 2 is changed according to the loss in the newly used transmission line, or the data corresponding to a plurality of types of transmission lines is previously stored in the register 2. The data is stored, and more appropriate data is selected and used at that time.

According to this embodiment, it is possible to perform loss compensation on an arbitrary transmission line. Further, according to the present embodiment, loss compensation can be realized without using a filter circuit using a coil, so that the driver circuit of this embodiment can be integrated. Furthermore, by integrating the driver circuit of this embodiment into an integrated circuit, it is possible to easily reduce the size and cost of the driver circuit of this embodiment.

Although the number of square wave generators is three in this embodiment, the number of square wave generators can be any number of one or more. As the number of square wave generators increases,
The waveform 16 after compensation at the transmission line end 9a can be brought closer to the original waveform 10.

Further, in the present embodiment, the square wave generator is configured to be capable of generating a square wave according to the pulse width data and the amplitude data stored in the register 2, but instead of this, The wave generator may be variable in only one of the pulse width and the amplitude, and the other may be fixed. For example, when the amplitude is fixed, the amplitude value in each square wave generator is the same. With this configuration, the storage area for storing fixed data of the pulse width data or the amplitude data can be omitted from the register 2.

Although the amplifier circuit 7 is used in this embodiment, if the adder 6 can drive the transmission line 9,
The amplifier circuit 7 can be omitted.

Another embodiment of the driver circuit having the transmission line loss compensating means according to the present invention will be described with reference to FIGS. The driver circuit 8 of this embodiment has a configuration for obtaining the pulse width and amplitude of a square wave necessary for compensating the loss of the transmission line.

As shown in FIG. 4, the driver circuit 8 of the present embodiment has the same configuration as that of the embodiment of FIG. 1 and has a signal generator 1 and a register for storing pulse width data and amplitude data of a square wave pulse. 2, square wave generators 3, 4, 5, ... Which generate square waves according to the pulse width data and amplitude data stored in register 2, output 1a of signal generator 1, output 3a of square wave generator 3, square Output 4a of the wave generator 4,
And an adder 6 for adding the outputs 5a of the square wave generator 5 ...
And an amplifier circuit 7 for amplifying the output 6a of the adder 6.

In this embodiment, the same components as those in the embodiment of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In addition to the above configuration, the driver circuit 8 of the present embodiment is further configured to obtain the pulse width and amplitude stored in the register 2 so as to digitize the waveform at the output end 7a of the amplifier circuit 7. It has a device 17 and an arithmetic device 18 for obtaining the pulse widths and amplitudes of the square wave 12, the square wave 13, the square wave 14 ... Based on the waveform obtained by the digitizing device 17.

The arithmetic unit 18 has an output terminal 7a of the amplifier circuit 7.
The waveform 11 at the transmission line end 9a is obtained on the basis of the digital data of the waveform which is detected by, and is reflected back at the transmission line end 9a through the transmission line 9 and further amplified before compensation of the transmission line loss. By comparing the output waveform 10 of the circuit 7 and the obtained waveform 11 (see FIGS. 2 and 3), both waveforms 10,
The pulse width and the amplitude of the square wave 12, the square wave 13, the square wave 14, ... Are obtained so that the difference of 11 is the minimum or less than or equal to a predetermined threshold value.

Of the processing operation in the driver circuit 8 of the present embodiment, the compensation value measurement processing, which is an example of the processing procedure for obtaining the pulse width and amplitude of each square wave for loss compensation, is shown in the flowchart of FIG. It demonstrates using. It should be noted that this processing is executed in a state in which the transmission line end 9a of the transmission line 9 connected to the driver circuit 8 of this embodiment is short-circuited or open.

In this process, first, after accepting the setting, which is input by the user or the like, that the transmission line end 9a is short-circuited or open (step 501), the transmission line loss is not compensated. That is, the signal from the signal generator 1 (see FIG. 2 or FIG. 3) is directly transmitted to the transmission line 9
The driver circuit 8 is operated so as to be supplied to (step 502). More specifically, by controlling the adder 6,
The addition of the square wave at this point is prohibited, or the square wave generators 3, 4, and 5 are controlled so that the square wave is not generated.

Next, the output waveform of the amplifier circuit 7 (hereinafter referred to as waveform 10) when the transmission line loss is not compensated by the digitizing device 17 and the waveform 10 passes through the transmission line 9 and is short-circuited or The reflected wave that is reflected by the open transmission line end 9a and returns is digitized (step 503). Here, the waveform 10 and the waveform 10
If the reflected waves of are overlapped (Yes in step 504)
s), the separation processing of both waveforms is performed by the arithmetic unit 18 (step 505).

Next, when the transmission line end 9a is set to be short-circuited (Yes in step 506), the waveform 10 is inverted at the time of reflection at the transmission line end 9a.
The computing device 18 inverts the reflected wave of the waveform 10 (step 507). Further, the arithmetic unit 18 calculates the difference between the waveform 10 and the reflected wave of the waveform 10 and halves the difference to obtain the difference A between the waveform 10 and the waveform 11 at the transmission line end 9a (step 508). .

Next, the difference between the waveform of the difference A between the waveform 10 and the waveform 11 and the waveform formed by adding the square wave 12, the square wave 13 and the square wave 14 is the minimum or a predetermined threshold value. The following pulse width and amplitude of each square wave are obtained by the arithmetic unit 18 (step 509), and the obtained pulse width and amplitude of each square wave are written in the register 2 (step 510).

According to the present embodiment, it is possible to obtain the pulse width and amplitude of the square wave pulse required for the loss compensation of any transmission line.

In the present embodiment, the waveform 11 when the waveform 10 is lost through the transmission line 9 is obtained by the arithmetic unit 18 using the waveform of the reflected wave of the waveform 10. The means for obtaining is not limited to this.
For example, another digitizing device 17 may be provided at the transmission line end 9a, the waveform 11 may be directly detected and digitized, and the data may be transferred to the arithmetic device 18. In such a case, it is not necessary to short-circuit or open the transmission line end 9a.

Another embodiment of the driver circuit having the transmission line loss compensating means according to the present invention will be described with reference to FIGS. The driver circuit of this embodiment uses a triangular wave instead of the square wave in the driver circuit of the embodiment shown in FIG.

The driver circuit 8 of this embodiment is, for example, as shown in FIG.
As shown in FIG. 1, according to the signal generator 1, the register 2 for storing the pulse width data and the amplitude data of the triangular wave pulse used for the loss compensation in the transmission line 9, and the pulse width data and the amplitude data stored in the register 2. , Which generate a triangular wave, an adder 6 for adding the output 1a of the signal generator 1, the output 19a of the triangular wave generator 19, and the output 20a of the triangular wave generator 20, and an adder 6
And an amplifier circuit 7 for amplifying the output 6a of the.

A method of compensating the transmission line loss by the driver circuit 8 of this embodiment will be described with reference to the waveform diagram of FIG. In the following description, the case where there are two triangular wave generators will be described. 7 (c) and 7 (d),
The result of adding the generated triangular wave pulses is shown.

The waveform 10 (FIG. 7A) is the output of the amplifier circuit 7 when the transmission line loss is not compensated. The waveform 10 is blunted like the waveform 11 (FIG. 7B) at the transmission line end 9a due to a loss such as a skin effect in the transmission line 9.
When the triangular wave 21 and the triangular wave 22 having different pulse widths and amplitudes are added to the waveform 11 at the same timing as the switching of the signal waveform to the Hi and Low states as shown in FIG. It can be seen that the waveform 10 is approached.

That is, the output waveform of the amplifier circuit 7 is shown in FIG.
As shown in (d), the waveform 15 is formed by adding the triangular wave 21 and the triangular wave 22 to the waveform 10, so that the transmission line end 9a has a waveform 16 similar to the waveform 10 (FIG. 7E). Can be obtained. Therefore, the transmission line loss can be compensated.

In the driver circuit 8 of the present embodiment, the magnitude and shape of the difference between the original waveform 10 and the waveform 11 that has undergone the loss in the transmission line 9 as described above is adapted (see FIG. 7 ( (See c)), the pulse width and amplitude of each triangular wave are obtained in advance as data and stored in the register 2.

Further, according to the pulse width data and the amplitude data stored in the register 2, the triangular wave generator 19 and the triangular wave generator 20 cause the triangular wave 19a and the triangular wave 20 to be generated.
The waveform 16 is obtained by generating a, adding it with the output 5a of the signal generator 5 by the adder 6, and amplifying the output 6a of the adder by the amplifier circuit 7.

Here, the triangular wave generator in this embodiment can change the pulse width and amplitude of the generated triangular wave. Therefore, when changing the transmission line, the data stored in the register 2 is changed according to the loss in the newly used transmission line, or the data corresponding to a plurality of types of transmission lines is stored in the register 2 in advance. Then, the more appropriate data is selected and used at that time.

According to the present embodiment, the loss compensation can be performed on an arbitrary transmission line, and the loss compensation can be realized without using a filter circuit using a coil. The example driver circuit can be integrated. Furthermore, by integrating the driver circuit into an integrated circuit, it is possible to easily reduce the size and cost of the driver circuit of this embodiment.

Further, since the present embodiment uses the triangular wave pulse, it is possible to more appropriately fill the difference between the waveform 10 and the waveform 11 with a smaller number of pulses as compared with the case of using the square wave pulse. Becomes Therefore, in the present embodiment, the transmission line loss compensation of the same quality is performed with a smaller number of triangular wave generators than the number of square wave generators used in the driver circuit shown in the embodiment of FIG. be able to.

In this embodiment, the number of triangular wave generators is two, but the number of triangular wave generators can be any number of 1 or more. As the number of triangular wave generators increases,
The waveform 16 after compensation at the transmission line end 9 a can be brought closer to the waveform 10.

Further, in the present embodiment, the triangular wave generator has a configuration in which the pulse width and amplitude of the generated triangular wave are variable, but instead of this, either the pulse width or the amplitude of the triangular wave generator is fixed. It may be configured as. For example, when the amplitude is fixed, the amplitude value of each triangular wave generator is the same. With such a configuration, the storage area for storing fixed data of the pulse width data or the amplitude data can be omitted from the register 2.

Although the amplifier circuit 7 is used in this embodiment, the amplifier circuit 7 can be omitted if the adder 6 can drive the transmission line.

Another embodiment of the driver circuit having the transmission line loss compensating means according to the present invention will be described with reference to FIG. The driver circuit 8 of this embodiment has a configuration for obtaining the pulse width and amplitude of a triangular wave necessary for compensating for the loss of the transmission line. In the embodiment of FIG. 4, the triangular wave is used instead of the square wave. is there.

As shown in FIG. 8, the driver circuit 8 of this embodiment includes a signal generator 1, a register 2 for storing pulse width data and amplitude data of a triangular wave pulse, and a register 2.
The triangular wave generators 19, 20 ... Which generate triangular waves in accordance with the pulse width data and the amplitude data stored in the above, and the output 1a of the signal generator 1, the output 19a of the triangular wave generator 19, and the output 20a of the triangular wave generator 20 are added. Adder 6 to
And an amplifier circuit 7 for amplifying the output 6a of the adder 6.

The driver circuit 8 of the present embodiment is further configured to obtain the pulse width and amplitude of the triangular wave pulse required for loss compensation of the transmission line, and digitizing for digitizing the waveform at the output end 7a of the amplifier circuit 7. The waveform 11 at the transmission line end 9a is obtained based on the device 17 and the digitized waveform at the output end 7a of the amplification circuit 7, and when the transmission line loss is not compensated, the output waveform 10 of the amplification circuit 7 and the waveform 11 (see FIG. 7), waveform 10 and waveform 11
Arithmetic unit 1 for obtaining the pulse widths and amplitudes of the triangular waves 21 and 22 whose difference with the minimum or less than or equal to a predetermined threshold
8 and.

As the processing for obtaining the pulse width and amplitude of the triangular wave pulse for the loss compensation in the driver circuit 8 of this embodiment, for example, in the compensation value measurement processing (see FIG. 5) of the embodiment of FIG. , A process using a triangular wave pulse instead of a square wave pulse is used. This process is
Similar to the above-mentioned compensation value measurement processing, it is executed with the transmission line end 9a being short-circuited or open.

That is, in this process, first, the driver circuit 8 is operated without compensation of the transmission line loss, and the output waveform of the amplifier circuit 7 when the transmission line loss is not compensated by the digitizing device 17. 10 and the reflected wave of the waveform 10 at the transmission line end 9a are detected and digitized. Here, when the waveform 10 and the reflected wave of the waveform 10 overlap, the separation processing is performed by the arithmetic unit 18. When the transmission line end 9a is short-circuited, the arithmetic unit 1
At 8, the reflected wave of waveform 10 is inverted.

Further, the arithmetic unit 18 calculates the difference between the waveform 10 and the reflected wave of the waveform 10 and halves the difference,
The difference between the waveform 10 and the waveform 11 at the transmission line end 9a is obtained. The difference waveform between the waveform 10 and the waveform 11 and the triangular wave 2
The pulse width and amplitude of each triangular wave whose difference with the waveform formed by adding 1 and the triangular wave 22 is the minimum or less than a predetermined threshold value is calculated by the arithmetic unit 18, and the pulse of each triangular wave is calculated. Write width and amplitude to register 2.

According to the present embodiment, it is possible to obtain the pulse width and amplitude of the triangular wave pulse necessary for the loss compensation of any transmission line.

Although the number of triangular wave generators is 2 in this embodiment, the number of triangular wave generators can be any number of 1 or more.

In this embodiment, the waveform 11 is replaced by the waveform 1
Based on the reflected wave of 0, it was calculated by the arithmetic unit 18,
It is also possible to provide another digitizing device at the transmission line end 9a, directly detect the waveform 11 and digitize it, and transfer the data to the arithmetic unit 18.
In this case, it is not necessary to short-circuit or open the transmission line end 9a.

Another embodiment of the driver circuit having the transmission line loss compensating means according to the present invention will be described with reference to FIGS.

In this embodiment, an example of a concrete configuration of a square wave generator in a driver circuit using a square wave as in the embodiment of FIG. 1 is shown. In the following description, when the transmission line loss at the time of the fall of the signal waveform generated by the signal generator (see FIG. 3) is compensated by using the square wave pulse generated by the two square wave generators. Will be described as an example.

As shown in FIG. 9, the driver circuit of this embodiment includes a signal generator 1, a register 2 for storing the pulse width data and amplitude data of a square wave pulse, and a pulse width data and a pulse width data stored in the register 2. Square wave generators 3 and 4 for generating a square wave pulse according to amplitude data, and a signal generator 1
1a, the output 3a of the square wave generator 3, and the output 4a of the square wave generator 4, and an amplifier circuit 7 for amplifying the output 6a of the adder 6.

The adder 6 and the square wave generators 3 and 4 each have a differential amplifier circuit which shares a resistor connected to the collector.

The square wave generator 3 delays the output 1 a of the signal generator 1 which is input to one input of the differential amplifier circuit included in the square wave generator 3 according to the pulse width data stored in the register 2. It has a variable delay circuit 23 and a variable current source 25 that changes the current value of the current flowing through the differential amplifier according to the amplitude data stored in the register 2.

The square wave generator 4, like the square wave generator 3, inputs the output 1a of the signal generator 1 which is input to one input of the differential amplifier circuit included in the square wave generator 4, to the register 2
The variable delay circuit 24 delays according to the pulse width data stored in the register 2, and the variable current source 26 changes the current value of the current flowing through the differential amplifier according to the amplitude data stored in the register 2.

The operation of the driver circuit of this embodiment is shown in FIG.
It will be described based on. Note that FIG. 10 shows the outputs 1a and 1b of the signal generator 1 of the present driver circuit, the square wave generators 3 and 4, and
3 is a waveform diagram showing the changes over time of the voltages at the outputs 23a and 24a of the variable delay circuit and the output 6a of the adder 6 and the changes over time of the currents at the outputs 3a and 4a of the square wave generators 3 and 4. . Further, in FIG. 10, t1 indicates the start timing of the trailing edge of the signal waveform, and t2, t3
Is a square wave generator 3, 4 stored in register 2.
It is the timing corresponding to each pulse width of the square wave generated in.

Before time t1, 1/2 of the current of the current source 25 flows in the output 3a of the square wave generator 3, and 1/2 of the current of the current source 26 flows in the output 4a of the square wave generator 4. Flowing. Therefore, the output 6a of the adder 6 has a voltage drop due to the sum of 1/2 of the current of the current source 25 flowing through the collector resistor 6b and 1/2 of the current of the current source 26 from the voltage at 6d in the figure. It becomes a voltage.

At time t1, the output 1a of the signal generator 1 changes to a predetermined low level (L) in response to the fall of the signal waveform.
When it changes from ow) to a high level (Hi), the current of the current source 25 flows through the output 3a of the square wave generator 3, and the current of the current source 26 flows through the output 4a of the square wave generator 4. Therefore, the output 6a of the adder 6 becomes a voltage obtained by subtracting the voltage drop due to the sum of the current of the current source 6c flowing through the collector resistor 6b, the current of the current source 25, and the current of the current source 26 from the voltage 6d.

At time t2, 2 generated for loss compensation
The delay circuit 23 corresponds to the end of the square wave pulse generated by the square wave generator 3, which is one of the two square wave pulses.
When the output 23a changes from Low to Hi, 1/2 of the current of the current source 25 flows to the output 3a of the square wave generator 3, and the current of the current source 26 flows to the output 4a of the square wave generator 4. . Therefore, the output 6a of the adder 6 is the voltage 6d
From the current of the current source 6c flowing through the collector resistor 6b, 1/2 of the current of the current source 25, and the current of the current source 26.

At time t3, the output 24 of the delay circuit 24 corresponds to the end of the square wave pulse generated by the square wave generator 4.
When a changes from Low to Hi, 1/2 of the current of the current source 25 flows through the output 3a of the square wave generator 3, and 1/2 of the current of the current source 26 flows through the output 4a of the square wave generator 4. Flows. Therefore, the output 6a of the adder 6 is calculated from the voltage 6d to the current of the current source 6c flowing through the collector resistor 6c, 1/2 of the current of the current source 21 and 1 of the current of the current source 21.
The voltage is the voltage obtained by subtracting the voltage drop due to the sum of / 2.

Therefore, at the output 6a of the adder 6, the current sources 25 and 26 of the square wave generators 3 and 4 and the variable delay circuit 2 are provided.
A waveform obtained by performing loss compensation on the transmission line for the falling portion of the signal waveform output from the signal generator 1 by using a square wave pulse having a pulse width and an amplitude controlled by 3 and 24 (Fig. 3 (d)) is formed.

According to this embodiment, since the pulse width of the square wave can be changed by the delay amount of the variable delay circuit and the amplitude of the square wave can be changed by the current amount of the current source, the data stored in the register 2 can be changed. By changing it, it is possible to perform loss compensation for an arbitrary transmission line.

In the present embodiment, the case where the loss compensation is performed for the falling portion of the signal waveform generated from the signal generator 1 has been described as an example. However, according to the configuration of the present embodiment, it is completely different from the above. Similarly, the loss compensation of the transmission line can be performed also for the rising portion of the signal waveform (see FIG. 2). Although the number of square wave generators is two, the number of square wave generators can be any number of one or more.

In this embodiment, both the delay circuit of the square wave generator and the current source are variable, but either one may be fixed. For example, when the current source is fixed, the current value of the current source of each square wave generator is the same. If one of them is fixed in this way, the storage area for storing the data corresponding to the fixed one of the pulse width data and the amplitude data can be omitted from the register 2.

In this embodiment, the collector resistance 6b of the adder 6 is connected to the characteristic impedance Zo of the transmission line 9.
If it is equal to, the amplifier circuit 7 can be omitted.

Another embodiment of the driver circuit having the transmission line loss compensating means according to the present invention will be described with reference to FIGS. 11 and 12.

In this embodiment, an example of a concrete configuration of a triangular wave generator in a driver circuit using a triangular wave is shown. In addition,
In the following description, an example will be described in which one triangular wave generator is used to perform loss compensation when the signal waveform generated from the signal generator falls.

As shown in FIG. 11, the driver circuit of this embodiment includes a signal generator 1, a register 2 for storing pulse width data and amplitude data of a triangular wave, a triangular wave generator 19 for generating a triangular wave pulse, An adder 6 for adding the output 1a of the signal generator 1 and the output 19a of the triangular wave generator 19
And an amplifier circuit 7 for amplifying the output 6a of the adder 6.

The adder 6 and the triangular wave generator 19 each have a differential amplifier circuit that shares a resistor connected to the collector.

The triangular wave generator 19 includes capacitors 19e, 1 connected to the inputs of the differential amplifier circuit included in the triangular wave generator 19.
9i, a pulse generator 19b that generates a pulse according to the amplitude data stored in the register 2 at the time of rising of the output 1a of the signal generator 1 and charges the capacitor 19e at the time of rising, and an output 1a of the signal generator 1 Pulse generator 19g that generates a pulse according to the amplitude data stored in the register 2 at the time of the fall and charges the capacitor 19i at the time of the fall.

The triangular wave generator 19 further includes a variable current source 19c that gradually absorbs the electric charge of the charged capacitor 19e.
And a variable current source 19h that gradually absorbs the electric charge of the charged capacity 19g.

The variable current sources 19c and 19h are connected to the register 2
The current value is made variable according to the pulse width data stored in, and the pulse width is adjusted by changing the speed at which the charge accumulated in the capacitors 19e and 19i is sucked out by this current value.

The operation of the driver circuit of this embodiment is shown in FIG.
It will be described based on. Note that FIG. 12 shows the changes over time in the voltages at the outputs 1a and 1b of the signal generator 1 of the present driver circuit, the output of the voltage source 19b of the triangular wave generator 19, and the output 6a of the adder 6, and also shows the triangular wave generator. It is a wave form diagram which shows the time change of the electric current in the output 19a of 19th. Also,
In FIG. 12, t1 indicates the start timing of the falling edge of the signal waveform, and t2 indicates the timing at which the triangular wave generated by the triangular wave generator 19 ends.

Output 1 of the triangular wave generator 19 before time t1
A half current of the current value I1 set by the current source 19d flows through 9a. Therefore, the output 6 of the adder 6
a is a voltage obtained by subtracting the voltage drop due to 1/2 of the current value I1 of the current source 19d flowing through the collector resistor 6b from the voltage at 6d in the figure.

At time t1, when the output 1a of the signal generator 1 changes from Low to Hi in response to the fall of the signal waveform, the amplitude data stored in the register 2 is generated by the pulse generator 19b. The capacitor 19e is charged by the pulse having the amplitude set by the above, and the current of the current value I2 flows through the output 19a of the triangular wave generator 19. Therefore, the output 6a of the adder 6 changes from the voltage 6d to the current of the current source 6c flowing through the collector resistance 6b and the current value I2.
The voltage will be the voltage with the voltage drop reduced by the sum of the current and the current.

Times t1 to t2 correspond to the inclined portion of the triangular wave pulse generated for loss compensation. That is,
The electric charge of the capacitor 19e charged at time t1 is gradually sucked out by the current source 19c of the triangular wave generator 19, and the current value flowing to the output 19a of the triangular wave generator 19 decreases. Therefore, the voltage of the output 6a of the adder 6 gradually rises.

After time t2, the output 1 of the triangular wave generator 19
A current half the current value I1 flows through 9a. Therefore, the output 6a of the adder 6 changes from the voltage 6d to the current of the current source 6c and 1 of the current value I1 flowing through the collector resistor 6b.
The voltage obtained by subtracting the voltage drop is the sum of the currents of / 2.

Therefore, at the output 6a of the adder 6, a signal is generated using a triangular wave pulse having a pulse width controlled by the variable current source 19c of the triangular wave generator 19 and an amplitude controlled by the pulse generator 19b. A waveform obtained by performing loss compensation on the transmission line is formed at the falling portion of the signal waveform output from the device 1.

According to this embodiment, the pulse width of the triangular wave can be changed by the current source 19c, and the amplitude of the triangular wave can be changed by the pulse generator 19b. Therefore, the loss compensation can be performed on an arbitrary transmission line only by changing the data stored in the register 2.

In the present embodiment, the case where the loss compensation is performed on the falling portion of the signal waveform generated from the signal generator 1 has been described as an example, but in the configuration of the present embodiment, the rising edge of the signal waveform is Correspondingly, by generating a pulse by the pulse generator 19g at the same time when the output 1a of the signal generator 1 falls, it is possible to perform loss compensation on the rising waveform in the same manner as above. Also,
Although the number of triangular wave generators is 1, the number of triangular wave generators can be any number of 1 or more.

Further, in this embodiment, both the pulse width and the amplitude of the triangular wave generator are variable, but either one may be fixed. For example, if the amplitude is fixed,
The amplitude value of each triangular wave generator is the same. In this way, when one is fixed, it is possible to omit from the register 2 the storage area for storing the data corresponding to the fixed one of the pulse width data and the amplitude data.

In this embodiment, the collector resistance 6b of the adder 6 is connected to the characteristic impedance Zo of the transmission line 9.
If it is equal to, the amplifier circuit 7 can be omitted.

An embodiment of the driver IC using the driver circuit having the transmission line loss compensating means according to the present invention,
This will be described with reference to FIG. The driver circuit included in the driver IC of this embodiment basically has the same configuration as the driver circuit of the embodiment of FIG. The same components as those of the embodiment shown in FIG. 1 are designated by the same reference numerals as those of the embodiment shown in FIG. 1, and the description thereof will be omitted.

As shown in FIG. 13, the driver IC 27 of this embodiment has a signal generator 1 and one or more terminals 27b for giving information such as timing and pattern to the signal generator 1.
, A register 2 for storing pulse width data and amplitude data of a square wave pulse, a terminal 27c for inputting information on the pulse width and amplitude stored in the register 2, and a terminal 27.
The serial / parallel converter 26 converts the serial data input to c into parallel data and supplies pulse width data and amplitude data to each storage area of the register 2.

In this embodiment, further, the square wave generators 3, 4, 5, ... Which generate square waves according to the pulse width data and the amplitude data stored in the register 2 and the output 1 of the signal generator 1.
a, the output 3a of the square wave generator 3, the output 4a of the square wave generator 4, the output 5a of the square wave generator 5, and an amplifier circuit 7 for amplifying the output 6a of the adder 6. When,
It has a terminal 27a for giving the output of the amplifier circuit 7 to the transmission line.

According to this embodiment, the driver circuit shown in FIG. 1 can be integrated on one chip without using the filter circuit having the coil. Further, since the driver circuit can be integrated on one chip, the driver circuit or the electronic device apparatus including the driver circuit can be downsized and the cost can be reduced.

Although the serial / parallel converter 26 is provided between the register 2 and the terminal 27c in this embodiment, the number of terminals is increased and the pulse width data and the amplitude data are directly stored in each storage area of the register 2. It may be configured to be stored.

Further, in the present embodiment, the driver circuit of the embodiment of FIG. 1 is used as the driver circuit of the driver IC 27, but instead, the driver circuits of the other embodiments described above (FIG. 4, FIG. 6, FIG. 8, FIG. 9, and FIG. 11) may be used. Since the driver circuits shown in FIGS. 4 and 8 have means for obtaining the pulse width and amplitude of the square wave or the triangular wave, when these circuit configurations are used, pulse width and amplitude data are externally supplied. The terminal 27c for receiving can be omitted.

An embodiment of a semiconductor test apparatus using a driver circuit or driver IC having transmission line loss compensating means according to the present invention will be described with reference to FIG.

The semiconductor test apparatus 37 of this embodiment is shown in FIG.
As shown in FIG. 5, a timing generator 29, a pattern generator 30, a waveform formatter 31, a digital comparator 32, a driver circuit 8 or driver IC 27 having a transmission line loss compensating means, an analog comparator 33, and a device under test. The element 34 is connected to the semiconductor testing device 37.
And a transmission line 9 for electrically connecting to.

In this embodiment, as the driver circuit 8,
Any of the driver circuits of the above-described embodiments (FIG. 1, FIG. 4,
6, FIG. 8, FIG. 9, and FIG. 11)). In addition, as the driver IC 27, as shown in FIG.
The driver IC 27 of the above embodiment can be used.

The driver circuit 8 shown in FIG.
When the driver circuit shown in FIG. 8 is used, the analog comparator 33 can be used as the digitizing device 17 included in the driver circuit 8.

In this embodiment, the timing signal 29a generated by the timing generator 29 and the test pattern 30a generated by the pattern generator 30 are combined by the waveform formatter 31, and the output thereof is tested by the driver circuit 8. The device under test 3 is passed through the transmission line 9 as a waveform 8a.
Given to 4.

The output signal 34a from the device under test 34 as a response of the test waveform 8a is converted into a voltage by the analog comparator 33 and converted into digital values of "0" and "1". The response signal from the device under test 34 after this digital conversion is output by the digital comparator 32.
A comparison test is performed with the expected value 30b, which is the response of the non-defective element created by the pattern generator 30, at the time indicated by the timing signal 29b, and the pass / fail thereof is determined.

According to this embodiment, since the driver circuit 8 or the driver IC 27 according to the present invention is used, the loss in the transmission line 9 is compensated when the test waveform 8a is sent to the device under test 34 through the transmission line 9. It becomes possible to do.

Further, according to the present embodiment, since the loss in the transmission line 9 can be compensated for, if the length of the transmission line 9 used is the same as that of the conventional semiconductor test apparatus, the test of higher frequency is performed. The waveform 8a can be given to the device under test 34, and the timing accuracy of the test waveform 8a can be improved. Further, if the same test frequency and the same timing speed as those of the conventional semiconductor test apparatus are used, the length of the transmission line 9 can be increased,
It is possible to improve the degree of freedom in the configuration and arrangement of the semiconductor test apparatus or the degree of freedom in operation.

An embodiment of a transmitting device for transmitting data through the transmission line using the driver circuit or driver IC having the transmission line loss compensating means according to the present invention will be described with reference to FIG.

The transmitter 35 of this embodiment is, for example, as shown in FIG.
As shown in FIG. 3, the driver circuit 8 or the driver IC 27 having the compensation means for the transmission line loss is provided, and
A signal having a frequency of MHz or more is transmitted to the receiving device 36 through the transmission line 9 of 50 cm or more.

In the present embodiment, the transmission device 35 and the reception device 36 refer to devices for transmitting and receiving signals such as data through the transmission line 9, and more specifically, the transmission device, the computer and computer peripheral equipment. , Network devices, measuring instruments, etc.

In this embodiment, the driver circuit 8 according to any one of the above-mentioned embodiments, which has a means for compensating for the transmission line loss (see FIGS. 1, 4, 6, 8, 9, and 11). Can be used as the driver circuit 8. Further, as the driver IC, the driver IC 27 of the embodiment shown in FIG. 10 can be used.

According to this embodiment, the loss of the transmission line 9 can be compensated, so that the transmission device 35 including the conventional transmission device, computer, computer peripheral equipment, network equipment, measuring instrument and the like can be used. In comparison, the transmission line 9
Of the same length, the higher frequency signal waveform 8a
Can be transmitted to the receiving device 36. Further, if the transmission frequency is the same, the length of the transmission line 9 can be increased, and the transmission device 35 and the reception device 36, which include a transmission device, a computer, computer peripheral devices, a network device, a measuring instrument, and the like. The degree of freedom of the configuration and arrangement of can be improved.

In this embodiment, the data frequency is 100M.
Hz or more, and the length of the transmission line 9 is 50 cm or more,
These conditions are merely examples. Generally speaking, under such a condition, in the conventional device configuration, the loss due to the skin effect in the transmission line begins to be remarkable, but according to the present embodiment, as described in each of the above embodiments, It is possible to compensate for the loss in the transmission line.

[0118]

According to the present invention, it is possible to compensate a loss in a transmission line in an arbitrary transmission line, and to provide a driver circuit suitable for an integrated circuit and a loss compensation method for the transmission line. be able to.

[0119]

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of an embodiment of a driver circuit having a transmission line loss compensating means according to the present invention.

FIG. 2A is a waveform diagram showing an output waveform 10 from the driver circuit when the loss compensation of the transmission line is not performed. FIG. 2B: Waveform 1 after waveform 10 has passed through the transmission line
The wave form diagram which shows 1. FIG. 2C: Explanatory diagram showing a square wave corresponding to the difference between the waveform 10 and the waveform 11. FIG. 2D: From the driver circuit according to the embodiment of FIG.
The waveform diagram which shows the output waveform 15 at the time of performing loss compensation. Figure 2 (e): Waveform 1 after waveform 15 has passed through the transmission line
6 is a waveform chart showing No. 6.

FIG. 3A is a waveform diagram showing an output waveform 10 from the driver circuit when the loss compensation of the transmission line is not performed. FIG. 3B: Waveform 1 after waveform 10 has passed through the transmission line
The wave form diagram which shows 1. FIG. 3C: Explanatory diagram showing a square wave corresponding to the difference between the waveform 10 and the waveform 11. FIG. 3D: From the driver circuit according to the embodiment of FIG.
The waveform diagram which shows the output waveform 15 at the time of performing loss compensation. Figure 3 (e): Waveform 1 after waveform 15 has passed through the transmission line
6 is a waveform chart showing No. 6.

FIG. 4 is a circuit diagram showing another embodiment of a driver circuit having a transmission line loss compensating means according to the present invention.

5 is a flowchart showing an example of a loss compensation value measurement processing procedure in the embodiment of FIG.

FIG. 6 is a circuit diagram showing another embodiment of a driver circuit having a transmission line loss compensating means according to the present invention.

FIG. 7A is a waveform diagram showing an output waveform 10 from the driver circuit when the loss compensation of the transmission line is not performed. FIG. 7B: Waveform 1 after waveform 10 has passed through the transmission line
The wave form diagram which shows 1. FIG. 7C: Explanatory diagram showing a square wave corresponding to the difference between the waveform 10 and the waveform 11. FIG. 7D: From the driver circuit according to the embodiment of FIG.
The waveform diagram which shows the output waveform 15 at the time of performing loss compensation. FIG. 7E: Waveform 1 after waveform 15 has passed through the transmission line
6 is a waveform chart showing No. 6.

FIG. 8 is a circuit diagram showing another embodiment of a driver circuit having a transmission line loss compensating means according to the present invention.

FIG. 9 is a circuit diagram showing another embodiment of a driver circuit having a transmission line loss compensating means according to the present invention.

10 is a waveform diagram for explaining the operation of the driver circuit of the embodiment of FIG.

FIG. 11 is a circuit diagram showing another embodiment of a driver circuit having a transmission line loss compensating means according to the present invention.

FIG. 12 is a waveform diagram for explaining the operation of the driver circuit of the embodiment of FIG.

FIG. 13 is a circuit diagram showing an embodiment of a driver IC using a driver circuit having a transmission line loss compensating means according to the present invention.

FIG. 14 is a circuit diagram showing an embodiment of a semiconductor test apparatus using a driver circuit or driver IC having a transmission line loss compensating means according to the present invention.

FIG. 15 is composed of a transmission device, a computer and computer peripherals, a network device, a measuring instrument, etc. for transmitting data through the transmission line using the driver circuit or the driver IC having the transmission line loss compensating means according to the present invention. FIG. 6 is a circuit diagram showing an example of a transmitted device.

[Explanation of symbols]

1 ... Signal generator 2 ... Registers 3, 4, 5 ... Square wave generator 6 ... Adder 7 ... Amplifier circuit 8 ... Driver circuit 9 ... Transmission line 10 ... Driver at the driver output end when loss compensation is not performed Output waveform 11 ... Driver output waveforms at the transmission line end when loss compensation is not performed 12, 13, 14 ... Square wave 15 ... Driver output waveform 16 at driver output end when loss compensation is performed ... Loss compensation Output waveform 17 of the driver at the end of the transmission line when performing ... Digitizing device 18 ... Arithmetic devices 19, 20 ... Triangle wave generators 21, 22 ... Triangle waves 23, 24 ... Variable delay circuits 25, 26 ... Variable current source 27 Driver IC 28 Serial / parallel converter 29 Timing generator 30 Pattern generator 31 Waveform formatter 32 Digital comparator 33 Analog comparator 34 ... Device under test 35 ... Transmitting device 36 ... Receiving device

Continuation of the front page (56) Reference JP-A-4-115727 (JP, A) JP-A-2-111126 (JP, A) JP-A-61-220530 (JP, A) Actual development Sho-56-33846 (JP , U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H03K 4/02 H03K 4/06 H03K 5/125

Claims (20)

(57) [Claims] 1. A driver circuit for transmitting a signal through a transmission line, wherein the driver circuit stores a width and an amplitude of a pulse added to a waveform of a signal to be transmitted, and the storage means. Pulse generating means for generating the pulse being generated at the rising and falling edges of the signal to be transmitted,
A driver circuit comprising: an addition unit that adds the signal to be transmitted and the pulse output from the pulse wave generator. 2. A driver circuit for transmitting a signal through a transmission line, the driver circuit including a storage means for storing at least one of a pulse width and an amplitude of a pulse added to a waveform of a signal to be transmitted. A pulse generation means for generating the pulse stored in the storage means at the rising and falling edges of the signal to be transmitted, and the signal to be transmitted and the pulse output from the pulse wave generator, A driver circuit comprising: 3. A driver circuit for transmitting a signal through a transmission line, the driver circuit comprising: a signal generator for generating a signal to be transmitted through the transmission line; and a waveform of the signal to be transmitted. A register for storing at least either the pulse width or the amplitude of the square wave pulse, which is set corresponding to the portion attenuated by the loss in the transmission line, and the square wave pulse stored in the register, Square wave generator generated at the rise and fall of the output waveform of, the adder for adding the output waveform of the signal generator and the output waveform of the square wave generator, and the output of the adder And an amplifier circuit for outputting to the transmission line. 4. The driver circuit according to claim 3 , wherein the output waveform from the amplifier circuit obtained in a state where the square wave pulse is not added to the output of the signal generator, and the output waveform are the transmission waveforms. A waveform acquisition unit that acquires a waveform after passing the line and a waveform obtained by the waveform acquisition unit before and after passing through the transmission line are compared, and the difference between the two waveforms is minimum or It further has an arithmetic circuit that obtains the pulse width and amplitude of each square wave pulse generated by the square wave generator that is less than or equal to a predetermined threshold value, and stores the obtained pulse width and amplitude in the register. A driver circuit characterized by the above. 5. A driver circuit according to claim 3 or 4, wherein the square wave generator includes a differential amplifier circuit for amplifying a difference between two inputs, information on the stored pulse width in the register According to the above, there is provided a delay circuit for delaying one input of the differential amplifier circuit, and a current source circuit for changing the current value of the drive current of the differential amplifier circuit according to the information on the amplitude stored in the register. A driver circuit characterized by the above. 6. A driver circuit for transmitting a signal through a transmission line, the driver circuit comprising: a signal generator for generating a signal to be transmitted through the transmission line; and a waveform of the signal to be transmitted. A register for storing at least either the pulse width or the amplitude of the triangular wave pulse, which is set corresponding to the portion attenuated by the loss in the transmission line, and the triangular wave pulse stored in the register, which is output from the signal generator. A triangular wave generator that is generated at the time of rising and falling of a waveform, an adder that adds the output waveform of the signal generator and the output waveform of the triangular wave generator, and amplifies the output of the adder, A driver circuit having an amplifier circuit for outputting to a transmission line. 7. The driver circuit according to claim 6 , wherein the output waveform from the amplifier circuit obtained in a state where the triangular wave pulse is not added to the output of the signal generator, and the output waveform is the transmission line. A waveform obtained after passing through the transmission line and a waveform obtained by the waveform obtaining means before and after passing through the transmission line are compared, and the difference between the two waveforms is minimum or predetermined. And a calculation circuit for calculating the pulse width and amplitude of each triangular wave pulse generated by the triangular wave generator, which is less than or equal to the threshold value, and storing the calculated pulse width and amplitude in the register. And driver circuit. 8. A driver circuit according to claim 6 or 7, wherein the triangular wave generator includes a differential amplifier circuit for amplifying a difference between two inputs, on at least one input of said differential amplifier circuit The capacitor is charged according to the connected capacity and the information about the amplitude stored in the register, according to the pulse generation circuit that changes the amplitude of the pulse for charging the capacity, and the information about the pulse width stored in the register. And a current source circuit that changes a current for gradually discharging charges. 9. A driver IC in which the driver circuit according to any one of claims 1 to 8 is formed on one integrated circuit. 10. A driver for transmitting a signal through a transmission line.
It ’s an Iva circuit, The driver circuit is The rise of the signal to be transmitted in said transmission line and
It is necessary to output a signal whose falling attenuation is compensated.
Storage means for storing the pulse width and amplitude of A pulse for generating a pulse stored in the storage means
Generating means, Output from the signal to be transmitted and the pulse generating means
And adding means for adding the pulse
Driver circuit to do. 11. A driver for transmitting a signal through a transmission line.
It ’s an Iva circuit, The driver circuit is The signal to be transmitted and the transmission line in the transmission line.
To compensate for the rising and falling edges of the signal
Is required and the driver circuit has its width and amplitude
Generate a memorized pulse, A signal to be transmitted and the pulse may be added and output.
And a driver circuit characterized by: 12. A driver for transmitting a signal through a transmission line.
It ’s an Iva circuit, The driver circuit is A signal generator for generating a signal to be transmitted through the transmission line
Raw ware, The rise of the signal to be transmitted in said transmission line and
A storage means for storing a compensation amount for compensating for the fall attenuation
Have, The signal to be transmitted is attenuated by the compensation amount.
A driver circuit characterized by outputting a signal. 13. The method according to any one of claims 10 to 12.
The driver circuit shown in The memory means of the driver circuit comprises a plurality of different pulses or
Is a driver characterized by storing a plurality of different compensation amounts.
Iva circuit. 14. The driver circuit according to claim 13.
hand, The plurality of pulses or the plurality of compensation amounts can be selected
A driver circuit characterized by: 15. The driver circuit according to claim 13.
hand, The plurality of pulses or the plurality of compensation amounts are
Selectable from outside the driver circuit according to line loss
A driver circuit characterized by being capable. 16. The driver circuit according to claim 13.
hand, The different pulses or the different compensation amounts
Of the rising and falling edges of the signal to be transmitted using
A driver circuit characterized by compensating for attenuation. 17. The driver circuit according to claim 13,
hand, The plurality of different pulses may be either width or amplitude.
A driver circuit characterized in that only one is different. 18. The driver according to claim 10 or 11.
A circuit, The pulse generating means for generating the pulse has two inputs.
A differential amplifier circuit for amplifying the difference, and the pulse width or
The pulse width stored in the storage means for storing the amplitude
Delays one input of the differential amplifier circuit according to information
A driver circuit characterized by the above. 19. The driver according to claim 10 or 11.
A circuit, The pulse generating means for generating the pulse has two inputs.
A differential amplifier circuit that amplifies the difference, The pulse width or amplitude is stored in a storage means
Driving the differential amplifier circuit according to the information on the generated amplitude.
A driver circuit characterized by changing the current value of the current
Road. 20. The method according to any one of claims 10 to 19.
Driver I characterized by using the above driver circuit
C.