CN115328087A - Primary side information detection circuit, method and chip of secondary side PD controller - Google Patents

Abstract

The circuit comprises a first acquisition module, a second acquisition module, a first comparator, an adder, a switch module and a controller, wherein the first acquisition module is used for acquiring VBUS voltage, the second acquisition module is used for acquiring VD platform voltage, and the sampling proportion of the first acquisition module and the second acquisition module is the same; when the voltage of the VD platform is larger than the sum of the VBUS voltage and the configured bias voltage, the first comparator is used for outputting a driving signal to the switch module so as to drive the switch module to be conducted; the switch module is used for generating an output signal according to the VD platform voltage in different on and off states; the controller is used for determining primary side information according to the pulse width and the pulse intensity of the output signal. The sampling circuit has the advantages of simple circuit structure, flexible configuration, high sampling precision and low cost.

Description

Primary side information detection circuit, method and chip of secondary side PD controller

technical field

The present application relates to the technical field of primary side information detection, in particular to a primary side information detection circuit, method and chip of a secondary side PD controller.

Background technique

The secondary side PD controller is usually used to control the power transistor connected to the secondary coil of the power system to control the output voltage on the secondary coil. In the application, it is necessary to detect the switching frequency, on-time, off-time and effective value of the line voltage of the primary controller.

However, the circuits used in the detection of the primary side information in the prior art are relatively complex, the detection cost is high, and the detection accuracy is low.

To sum up, there are problems in the prior art that the detection circuit of the primary side information is complicated and the detection cost is high.

Contents of the invention

The purpose of the present application is to provide a primary side information detection circuit, method and chip of a secondary side PD controller, so as to solve the problems in the prior art that the primary side information detection circuit is complicated and the detection cost is high.

In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

In the first aspect, an embodiment of the present application provides a primary side information detection circuit of a secondary side PD controller, the circuit includes a first acquisition module, a second acquisition module, a first comparator, an adder, a switch module, and A controller, the first acquisition module is electrically connected to the adder, the adder is also electrically connected to the first input terminal of the first comparator, and the second acquisition module is electrically connected to the first comparator The second input end of the first comparator is electrically connected, the output end of the first comparator is electrically connected to the switch module, and the switch module is also electrically connected to the second acquisition module and the controller; wherein,

The first collection module is used to collect the VBUS voltage, the second collection module is used to collect the VD platform voltage, and the sampling ratio of the first collection module and the second collection module is the same;

The adder is used to add the VBUS voltage and the configured bias voltage and then output to the first comparator;

When the VD platform voltage is greater than the sum of the VBUS voltage and a configured bias voltage, the first comparator is used to output a driving signal to the switch module to drive the switch module to conduct;

The switch module is used to generate an output signal according to the VD platform voltage under different on and off states;

The controller is used for determining primary side information according to the pulse width and pulse intensity of the output signal.

Optionally, the first acquisition module includes an acquisition unit and a filter unit, the acquisition unit is electrically connected to the first input end of the adder, and the input end of the acquisition unit is also grounded through the filter unit, The collection unit is used to collect the VBUS voltage, the second input terminal of the adder is used to receive the configured bias voltage, and the output terminal of the adder is electrically connected to the first input terminal of the first comparator; in,

The adder is used to add the VBUS voltage and the configured bias voltage to the first input terminal of the comparator.

Optionally, the acquisition unit includes a first resistor and a second resistor, one end of the first resistor and the second resistor connected in series with the main circuit to collect the VBUS voltage, the other end is grounded, and the adder The first input terminal of is connected between the first resistor and the second resistor.

Optionally, the primary side information detection circuit of the secondary side PD controller further includes a second comparator, the first input terminal of the second comparator is used to receive a preset voltage, and the second comparator's The second input terminal is electrically connected to the second acquisition module, and the output terminal of the second comparator is electrically connected to the second input terminal of the adder; wherein,

The second comparator is used to generate a bias voltage and transmit the bias voltage to a second input terminal of the adder.

Optionally, the second collection module includes a third resistor and a fourth resistor, one end of the third resistor connected in series with the fourth resistor is used to collect the VD platform voltage, the other end is grounded, and the first comparison The second input terminal of the device and the switch module are both connected between the third resistor and the fourth resistor.

Optionally, the switch module includes a transmission gate, the gate of the transmission gate is electrically connected to the output terminal of the first comparator, the input terminal of the transmission gate is electrically connected to the second acquisition module, and the The output terminal of the transmission gate is electrically connected with the controller.

Optionally, the primary side information detection circuit of the secondary side PD controller further includes a first capacitor, a second capacitor, a buffer, and a fifth resistor, and one end of the buffer and the first capacitor is connected to the The switch module is electrically connected, the other end of the first capacitor is grounded, the other end of the buffer is electrically connected to one end of the fifth resistor, and the other end of the fifth resistor is electrically connected to the controller, And the other end of the fifth resistor is grounded through the second capacitor.

In a second aspect, an embodiment of the present application further provides a detection chip, where the detection chip includes the above-mentioned primary side information detection circuit of the secondary side PD controller.

In the third aspect, the embodiment of the present application also provides a primary side information detection method of the secondary side PD controller, which is applied to the above primary side information detection circuit of the secondary side PD controller, and the method includes:

Collect VBUS voltage and VD platform voltage;

generating an output signal according to the sum of the VBUS voltage and the configured bias voltage, and the VD platform voltage;

The primary side information is determined according to the pulse width and pulse intensity of the output signal.

Optionally, the step of generating an output signal according to the sum of the VBUS voltage and a configured bias voltage, and the VD platform voltage includes:

Using an adder to add the VBUS voltage and the configured bias voltage to generate an output signal with the VD platform voltage; wherein the configured bias voltage is generated according to the VD platform voltage and a preset voltage.

Compared with the prior art, the present application has the following beneficial effects:

This application provides a primary side information detection circuit, method and chip of a secondary side PD controller. The circuit includes a first acquisition module, a second acquisition module, a first comparator, an adder, a switch module and a controller. The second An acquisition module is electrically connected to the adder, the adder is also electrically connected to the first input end of the first comparator, the second acquisition module is electrically connected to the second input end of the first comparator, and the output end of the first comparator is electrically connected to the second input end of the first comparator. The switch module is electrically connected, and the switch module is also electrically connected to the second acquisition module and the controller respectively; wherein, the first acquisition module is used to acquire the VBUS voltage, the second acquisition module is used to acquire the VD platform voltage, and the first acquisition module is connected to the second acquisition module. The sampling ratio of the two acquisition modules is the same; the adder is used to add the VBUS voltage and the configured bias voltage and then output to the first comparator. When the VD platform voltage is greater than the sum of the VBUS voltage and the configured bias voltage, the second A comparator is used to output a driving signal to the switch module to drive the switch module to be turned on; the switch module is used to generate an output signal according to the VD platform voltage in different on and off states; the controller is used to generate an output signal according to the pulse width, pulse The intensity determines the primary side information. Since the circuit module provided by the present application is relatively simple, its cost is relatively low. Moreover, by collecting and comparing the sum of the VD platform voltage, the VBUS voltage and the configured bias voltage, the primary side information can be determined with higher accuracy.

In order to make the above-mentioned purpose, features and advantages of the present application more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 shows a system block diagram of a secondary side PD controller in the prior art.

FIG. 2 shows a schematic diagram of a secondary side VDS waveform in the prior art.

FIG. 3 shows a block diagram of a primary side information detection circuit of a secondary side PD controller provided by an embodiment of the present application.

FIG. 4 shows a schematic circuit diagram of a primary side information detection circuit of a secondary side PD controller provided by an embodiment of the present application.

Fig. 5 shows an exemplary flowchart of a method for detecting primary side information of a secondary side PD controller provided by an embodiment of the present application.

In the picture:

110-first acquisition module; 120-second acquisition module; 130-adder; 140-first comparator; 150-switch module; 160-controller; 170-second comparator.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of them. The components of the embodiments of the application generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second" and the like are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. any such actual relationship or order exists between them.

Some implementations of the present application will be described in detail below in conjunction with the accompanying drawings. In the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

As mentioned in the background art, the secondary side PD controller is usually used to control the power transistor connected to the secondary coil of the power supply system to control the output voltage on the secondary coil. In the application, the secondary side PD controller The system diagram is shown in Figure 1.

As shown in Figure 1, the PD controller on the secondary side is connected to the secondary coil. By obtaining the information on the secondary coil, it controls the on-off state and on-off frequency of the power transistor on the main circuit, and then controls the power on the secondary coil. The output voltage is controlled.

However, the relevant detection circuit is relatively complicated at present. In view of this, the embodiment of the present application provides a primary side information detection circuit of the secondary side PD controller, and realizes the detection of the primary side information through a relatively simple circuit structure. Reduced costs.

The following is an exemplary description of the primary side information detection circuit of the secondary side PD controller provided by this application:

As an optional implementation, please refer to FIG. 2, the circuit includes a first acquisition module 110, a second acquisition module 120, a first comparator 140, an adder 130, a switch module 150 and a controller 160, the first acquisition The module 110 is electrically connected with the adder 130, and the adder 130 is also electrically connected with the first input end of the first comparator 140, and the second acquisition module 120 is electrically connected with the second input end of the first comparator 140, and the first comparator The output terminal of 140 is electrically connected with the switch module 150, and the switch module 150 is also electrically connected with the second collection module 120 and the controller 160 respectively; wherein, the first collection module 110 is used for collecting the VBUS voltage, and the second collection module 120 is used for collecting VD platform voltage, and the sampling ratio of the first acquisition module 110 and the second acquisition module 120 is the same; the adder 130 is used to add the VBUS voltage and the configured bias voltage and output it to the first comparator 140 when When the VD platform voltage is greater than the sum of the VBUS voltage and the configured bias voltage, the first comparator 140 is used to output a drive signal to the switch module 150 to drive the switch module 150 to conduct; In the off state, the output signal is generated according to the VD platform voltage; the controller 160 is used to determine the primary side information according to the pulse width and pulse intensity of the output signal.

Among them, the VD platform voltage mentioned in this application refers to the voltage on the secondary side of the transformer, and it satisfies the formula:

VD platform voltage = VBUS+VIN/NPS;

Among them, the VBUS voltage represents the output voltage of the secondary side, VIN is the equivalent value of the AC power supply voltage output by the primary side, and NPS is the primary and secondary side turns ratio of the transformer.

Because the second collection module 120 can collect the VD platform voltage, the first collection module 110 can collect the VBUS voltage, and drive the conduction of the switch module 150 through a comparison mode, and when the switch module 150 is turned on, the second collection module 120 can be The VD platform voltage is output to the controller 160; when the switch module 150 is turned off, the second acquisition module 120 cannot output the VD platform voltage to the controller 160, so that the output signal through the switch module 150 is actually a continuous pulse signal.

Since the output signal is directly related to the voltage of the VD platform, and the frequency of the voltage after being transformed by the transformer remains unchanged, only the magnitude of the voltage changes. On this basis, the frequency, turn-on time, turn-off time and primary side voltage of the switching signal of the primary side controller 160 can be determined according to the pulse width and pulse strength of the output signal (the pulse strength represents the voltage value). The master controller 160 provides complete primary side information, thereby meeting the system decision-making requirements of the master controller 160 .

During normal operation, the VDS waveform on the SR (secondary) side varies according to the effective value of the line voltage VIN and the load, as shown in Figure 3. In this figure, VIN is the equivalent value of the primary output AC power supply voltage, and NPS is Transformer primary to secondary turns ratio. Since the VDS waveform changes with the effective value of VIN and the switching frequency, and there will be a resonant sinusoidal waveform that interferes with the correct sampling of the line voltage information, in order to detect the switching frequency of the primary controller and the effective value of the line voltage from the VDS waveform on the SR (secondary) side , it is necessary to take an appropriate comparison threshold to compare with this waveform, and at the same time, it is necessary to compare the platform voltage of the VDS waveform.

Therefore, as an implementation, referring to FIG. 4, the first acquisition module 110 includes an acquisition unit and a filter unit, the acquisition unit is electrically connected to the first input end of the adder 130, and the input end of the acquisition unit is also grounded through the filter unit , the collection unit is used to collect the VBUS voltage, the second input terminal of the adder 130 is used to receive the bias voltage, and the output terminal of the adder 130 is electrically connected to the first input terminal of the first comparator 140; wherein, the adder 130 is used for The sum of the VBUS voltage and the bias voltage is output to the first input terminal of the comparator. The filtering unit may be a capacitor, and the filtering function of the VBUS voltage is realized through the capacitor.

Moreover, the primary side information detection circuit of the secondary side PD controller 160 also includes a second comparator 170, the first input terminal of the second comparator 170 is used to receive a preset voltage, and the second input terminal of the second comparator 170 It is electrically connected to the second acquisition module 120, and the output terminal of the second comparator 170 is electrically connected to the second input terminal of the adder 130; wherein, the second comparator 170 is used to generate a bias voltage, and transmit the bias voltage to The second input terminal of the adder 130 .

The acquisition unit includes a first resistor and a second resistor. One end of the first resistor and the second resistor connected in series is connected to the main circuit to collect the VBUS voltage, and the other end is grounded. The first input end of the adder 130 is connected to the first resistor and the second resistor. between the second resistor. Wherein, the sampling ratio of this application is 50:1.

The second acquisition module 120 includes a third resistor and a fourth resistor, one end of the third resistor and the fourth resistor connected in series is used to collect the VD platform voltage, the other end is grounded, the second input end of the first comparator 140, the switch module 150 Both are connected between the third resistor and the fourth resistor.

The switch module 150 includes a transmission gate, the gate of which is electrically connected to the output terminal of the first comparator 140 , the input terminal of the transmission gate is electrically connected to the second acquisition module 120 , and the output terminal of the transmission gate is electrically connected to the controller 160 .

The primary side information detection circuit of the secondary side PD controller 160 also includes a first capacitor, a second capacitor, a buffer and a fifth resistor, one end of the buffer and the first capacitor is electrically connected to the switch module 150, and the first capacitor The other end is grounded, the other end of the buffer is electrically connected to one end of the fifth resistor, the other end of the fifth resistor is electrically connected to the controller 160 , and the other end of the fifth resistor is grounded through the second capacitor.

So this application works as follows:

The VBUS voltage is sampled by a 10:1 resistor network, and then a 5:1 ratio circuit is used to obtain one-fiftieth of the VBUS voltage, which is added to the high-side bias voltage OS_HS to obtain TH_HS and compare it with the VD voltage to obtain the VDS ON signal ON Signal. The VDS frequency can be calculated from the interval time between the two ON signals, and the ON Signal samples the VD platform voltage VBUS+VIN/NPS through the transmission gate TG1 after the BlankingTime delay, and the sampled VD platform voltage is stored in the voltage information through the Buffer In the second capacitor, the system calculates the primary voltage value according to the output voltage. Moreover, the VDS on signal and off signal are obtained from the high-side comparator, and thus the on time On time of the VDS signal can be calculated, and the VDS can be obtained from the timing from the VDS off signal to the first rising edge time of the fixed voltage comparator. Signal off time Offtime.

On the basis of the above implementation manners, an embodiment of the present application further provides a detection chip, which includes the above primary side information detection circuit.

In addition, please refer to FIG. 5 , the embodiment of the present application also provides a primary side information detection method of the secondary side PD controller 160, the method includes:

S102, collecting VBUS voltage and VD platform voltage.

S104. Generate an output signal according to the sum of the VBUS voltage and the configured bias voltage, and the VD platform voltage.

S106. Determine primary side information according to the pulse width and pulse intensity of the output signal.

Optionally, S104 includes:

The adder is used to add the VBUS voltage and the configured bias voltage to generate an output signal with the VD platform voltage; wherein, the configured bias voltage is generated according to the VD platform voltage and the preset voltage.

The following is an exemplary description of the high voltage input protection circuit provided by this application:

To sum up, this application provides a primary side information detection circuit, method and chip of a secondary side PD controller. The circuit includes a first acquisition module, a second acquisition module, a first comparator, an adder, and a switch module And the controller, the first acquisition module is electrically connected with the adder, the adder is also electrically connected with the first input end of the first comparator, the second acquisition module is electrically connected with the second input end of the first comparator, and the first comparison The output end of the device is electrically connected to the switch module, and the switch module is also electrically connected to the second acquisition module and the controller respectively; wherein, the first acquisition module is used to collect the VBUS voltage, the second acquisition module is used to collect the VD platform voltage, and the second acquisition module is used to collect the VBUS voltage. The sampling ratio of the first acquisition module and the second acquisition module is the same; the adder is used to add the VBUS voltage and the configured bias voltage and then output to the first comparator, when the VD platform voltage is greater than the VBUS voltage and the configured bias voltage In the sum, the first comparator is used to output a driving signal to the switch module to drive the switch module to be turned on; the switch module is used to generate an output signal according to the VD platform voltage in different on and off states; the controller is used to The pulse width and pulse intensity determine the primary side information. Since the circuit module provided by the present application is relatively simple, its cost is relatively low. Moreover, by collecting and comparing the sum of the VD platform voltage, the VBUS voltage and the configured bias voltage, the primary side information can be determined with higher accuracy.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, various modifications and changes may be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, but that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and not restrictive in all points of view, and the scope of the application is defined by the appended claims rather than the foregoing description, and it is intended that the scope of the present application be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in this application. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (10)

1. A primary side information detection circuit of a secondary side PD controller, characterized in that the circuit comprises a first acquisition module, a second acquisition module, a first comparator, an adder, a switch module and a controller, and the The first acquisition module is electrically connected to the adder, and the adder is also electrically connected to the first input terminal of the first comparator, and the second acquisition module is electrically connected to the second input terminal of the first comparator. Terminals are electrically connected, the output terminal of the first comparator is electrically connected to the switch module, and the switch module is also electrically connected to the second acquisition module and the controller; wherein, The first collection module is used to collect the VBUS voltage, the second collection module is used to collect the VD platform voltage, and the sampling ratio of the first collection module and the second collection module is the same; The adder is used to add the VBUS voltage and the configured bias voltage and then output to the first comparator; When the VD platform voltage is greater than the sum of the VBUS voltage and a configured bias voltage, the first comparator is used to output a driving signal to the switch module to drive the switch module to conduct; The switch module is used to generate an output signal according to the VD platform voltage under different on and off states; The controller is used for determining primary side information according to the pulse width and pulse intensity of the output signal. 2. The primary side information detection circuit of secondary side PD controller as claimed in claim 1, is characterized in that, described first acquisition module comprises acquisition unit and filter unit, the first of described acquisition unit and described adder One input end is electrically connected, and the input end of the acquisition unit is also grounded through the filter unit, the acquisition unit is used to collect the VBUS voltage, and the second input end of the adder is used to receive the configured bias voltage, The output end of the adder is electrically connected to the first input end of the first comparator; wherein, The adder is used to add the VBUS voltage and the configured bias voltage to the first input terminal of the comparator. 3. The primary side information detection circuit of the secondary side PD controller as claimed in claim 2, wherein the acquisition unit includes a first resistor and a second resistor, and the first resistor and the second resistor One end of the series connection is connected to the main circuit to collect the VBUS voltage, and the other end is grounded. The first input end of the adder is connected between the first resistor and the second resistor. 4. The primary side information detection circuit of the secondary side PD controller as claimed in claim 1, is characterized in that, the primary side information detection circuit of the secondary side PD controller also includes a second comparator, the first The first input end of the second comparator is used to receive the preset voltage, the second input end of the second comparator is electrically connected to the second acquisition module, and the output end of the second comparator is connected to the adder The second input terminal is electrically connected; where, The second comparator is used to generate a bias voltage and transmit the bias voltage to a second input terminal of the adder. 5. The primary side information detection circuit of the secondary side PD controller according to claim 1, wherein the second acquisition module includes a third resistor and a fourth resistor, and the third resistor and the first resistor One end of the four resistors connected in series is used to collect the VD platform voltage, and the other end is grounded. The second input end of the first comparator and the switch module are both connected between the third resistor and the fourth resistor. 6. The primary side information detecting circuit of secondary side PD controller as claimed in claim 1, is characterized in that, described switch module comprises transmission gate, and the gate pole of described transmission gate and the output of described first comparator The terminals are electrically connected, the input terminal of the transmission gate is electrically connected to the second acquisition module, and the output terminal of the transmission gate is electrically connected to the controller. 7. The primary side information detection circuit of the secondary side PD controller as claimed in claim 1, is characterized in that, the primary side information detection circuit of the secondary side PD controller also includes a first capacitor, a second capacitor, A buffer and a fifth resistor, one end of the buffer and the first capacitor are electrically connected to the switch module, the other end of the first capacitor is grounded, and the other end of the buffer is connected to the fifth One end of the resistor is electrically connected, the other end of the fifth resistor is electrically connected to the controller, and the other end of the fifth resistor is grounded through the second capacitor. 8. A detection chip, characterized in that the detection chip comprises the primary side information detection circuit of the secondary side PD controller according to any one of claims 1 to 7. 9. A primary side information detection method of a secondary side PD controller, characterized in that it is applied to the primary side information detection circuit of the secondary side PD controller as claimed in any one of claims 1 to 7, said Methods include: Collect VBUS voltage and VD platform voltage; generating an output signal according to the sum of the VBUS voltage and the configured bias voltage, and the VD platform voltage; The primary side information is determined according to the pulse width and pulse intensity of the output signal. 10. The primary side information detection method of the secondary side PD controller as claimed in claim 9, characterized in that, the step of generating an output signal according to the sum of the VBUS voltage and the configured bias voltage and the VD platform voltage include: Using an adder to add the VBUS voltage and the configured bias voltage to generate an output signal with the VD platform voltage; wherein the configured bias voltage is generated according to the VD platform voltage and a preset voltage.

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