CN100420020C

CN100420020C - Integrated circuit chip with built-in high precision frequency oscillator

Info

Publication number: CN100420020C
Application number: CNB2003101088740A
Authority: CN
Inventors: 尤炜
Original assignee: ZHONGYING ELECTRONICS (SHANGHAI) CO Ltd
Current assignee: SINO WEALTH ELECTRONIC Ltd; Sino Wealth Microelectronics Co ltd
Priority date: 2003-11-26
Filing date: 2003-11-26
Publication date: 2008-09-17
Anticipated expiration: 2023-11-26
Also published as: CN1622329A

Abstract

The present invention provides an integrated circuit chip with a built-in high-accuracy frequency vibrator. A clock source of a traditional chip is usually realized by using a vibration device with high external connection accuracy to match a vibration circuit in an integrated circuit chip, and has the problems: 1. as a vibration device needs externally connecting, the component cost can be increased; 2. the chip needs to provide foot positions for externally connecting a vibration device; functions of other input/output pipe pins can not be favorably expanded because of the limitation of the pipe pin quantity of the chip. The integrated circuit chip with a built-in frequency vibrator of the present invention comprises an inner circuit for realizing basic functions of the chip, and an inner vibration circuit which is connected with the inner circuit and is used for providing a clock source required by the inner part, wherein the inner vibration circuit comprises an: RC vibration circuit which is composed of a resistor and a capacitor and is used for generating vibration signals, and a frequency adjusting circuit which is connected with the RC vibration circuit and is used for adjusting the frequency of the vibration signals generated by the RC vibration circuit.

Description

The integrated circuit (IC) chip of built-in high accuracy frequency oscillator

Technical field

The present invention relates to integrated circuit (IC) chip, relate in particular to built-in frequency oscillator in integrated circuit (IC) chip.

Background technology

Electronic technology develops into today, and integrated circuit has become a very general electronic device.Often, integrated circuit is because the needs of internal circuit and function all need to provide the clock source.At present, clock source in the integrated circuit normally utilizes the higher oscillating device of external precision (as Crystal crystal oscillator, Ceramic ceramic resonator etc.) to cooperate the oscillating circuit of integrated circuit (IC) chip inside to be achieved, and the frequency that so can obtain degree of precision guarantees.

Fig. 1 shows a kind of structural representation of the common external oscillating element of integrated circuit.As shown in Figure 1, chip IC 1 except internal circuit 11, an also external crystal oscillator CR and two capacitor C10 and C20 in the outside of chip IC 1.These outward elements constitute a typical high precision oscillator with the reverser 0A and a resistor R of chip internal, for the internal circuit 11 of chip IC 1 provides its needed clock signal.

Though traditional this mode provides the high accuracy clock source for chip, it faces two problems: one, because want external oscillating device, so the assembly cost will increase; Two, chip must provide external oscillator used pin position.Owing to be subjected to the limitation of chip pin number, the function amplification of so just unfavorable other I/O (I/O) pin.

Summary of the invention

Edge this, the problem at above-mentioned prior art exists the object of the present invention is to provide a kind of external oscillating device that need not, and utilizes the technical scheme of built-in RC oscillating circuit, saves chip oscillator pin and external device, the high integrated application demand of realization system.

According to above-mentioned purpose, the invention provides a kind of integrated circuit (IC) chip of built-in frequency oscillator, this chip comprises:

One internal circuit is used to realize the basic function of chip; With

Internal oscillator circuit links to each other with described internal circuit, is used for providing needed clock source to described internal circuit;

Described internal oscillator circuit comprises:

The RC oscillating circuit is made of the resistor and the capacitor of a plurality of serial connections, is used to produce oscillator signal, and the resistor of a plurality of serial connections forms resistance series circuit, an end of this resistor in series circuit and each resistor be connected in series a little between stride and establish an electronic switch; And

Frequency adjustment circuit links to each other with described RC oscillating circuit, is used to regulate the frequency of the oscillator signal that described RC oscillating circuit produces, and this frequency adjustment circuit comprises:

One pre-adjustment value register is used to store one group of pre-adjustment value;

One programming value register is used to store the pre-adjustment value through adjusting;

Two select a selector, link to each other with this programming value register with this pre-adjustment value register, and this two selects the control signal that a selector receive to be selected the pre-adjustment value in this pre-adjustment value register, and exports one of this group pre-adjustment value;

Decoding circuit two is selected a selector and is linked to each other with this, receives this two pre-adjustment value of selecting selector output, offers this RC oscillating circuit after decoding, is used to control described electronic switch;

Measure this RC oscillating circuit frequency of oscillation of this moment by the design test passage, pass through one group of pre-adjustment value of this pre-adjustment value register then, select corresponding adjusted value, make the frequency of oscillation of this RC oscillator reach designing requirement, then the pre-adjustment value of this moment is deposited in this programming value register.

As mentioned above, integrated circuit (IC) chip provided by the invention has been saved traditional external oscillating device by the mode of built-in RC oscillating circuit, has reduced the cost of assembly on the one hand, for chip provides unnecessary pin position, helps the amplification of chip functions on the other hand.Moreover, by frequency adjustment circuit, guaranteed the frequency accuracy of the oscillating circuit of chip built-in.

Describe specific embodiments of the invention in detail below in conjunction with accompanying drawing, above-mentioned and other advantage, feature and effect of the present invention will further be understood by following detailed.

Description of drawings

Fig. 1 is the circuit diagram of the traditional external oscillating element of integrated circuit;

Fig. 2 is the circuit block diagram of the integrated circuit (IC) chip of built-in frequency oscillator of the present invention;

Fig. 3 is the circuit diagram of the RC oscillating circuit among Fig. 2;

Fig. 4 is the schematic diagram of the frequency adjustment circuit among Fig. 2.

Embodiment

As shown in Figure 2, integrated circuit (IC) chip of the present invention has changed the structure that traditional chip needs external oscillating device, chip internal built-in high-precision frequency oscillation circuit.Integrated circuit (IC) chip of the present invention also comprises RC oscillating circuit 12 and frequency adjustment circuit 13 except the internal circuit 11 that comprises integrated circuit itself and have.RC oscillating circuit 12 is used to produce internal circuit 11 needed oscillator signals, and provides to it; Frequency adjustment circuit 13 is used to regulate the frequency of the oscillator signal that RC oscillating circuit 12 produces, with the precision of the frequency that improves the oscillator signal that produces.

Fig. 3 is the circuit diagram of the RC oscillating circuit 12 among Fig. 2.This RC oscillating circuit 12 generally comprises: a capacitor C, a reverser OA and a resistor in series circuit R1, R2 ..., RN.Capacitor C, resistor in series circuit and reverser constitute a common oscillating circuit, and the frequency values of the oscillator signal of its output is by the resistance decision of capacitor C and resistance series circuit.When the value of capacitor C design hour, the characterisitic parameter of this RC oscillating circuit will depend primarily on the resistance of resistor in series circuit.

As shown in Figure 3, an end points JN of resistor in series circuit and each resistor R 1, R2 ..., serial connection point J1, the J2 of RN ..., stride between the JN-1 establish electronic switch K1, a K2 ..., KN-1.Owing to be used as the material of resistor in chip, for example POLY (polysilicon) etc. is subjected to the bias effect of manufacturing process easily, and makes the resistor resistance of making have skew, therefore, has designed said structure among the present invention.After integrated circuit (IC) chip completes, by control electronic switch K1, K2 ..., the keying of KN-1, resistance that can the regulating resistor series circuit, thus improve RC oscillating circuit 12 precision.Certainly, in the present embodiment, be as an example, but be appreciated that in a further embodiment with the resistor in series circuit, also can the capacitor parallel circuits or mode that both combine realize.

Fig. 4 shows the schematic diagram of the frequency adjustment circuit 13 among Fig. 2.Frequency adjustment circuit 13 is used to regulate the frequency of the oscillator signal that RC oscillating circuit 12 produces.Specifically, frequency adjustment circuit 13 by electronic switch K1, K2 in the control RC oscillating circuit 12 ..., the keying of KN-1, regulate its frequency of oscillation.

As shown in Figure 4, frequency adjustment circuit 13 comprises that a pre-adjustment value register 31, programming value register 32, two select a selector 33 and decoding circuit 34.Pre-adjustment value register 31 has been stored one group of pre-adjustment value, and the output of pre-adjustment value register 31 and programming value register 32 is connected to two and selects on the selector 33.After integrated circuit (IC) chip completes by said structure, select the control signal Ctl that the input of pre-adjustment value register 31 is selected in a selector 33 inputs to two, after decoding circuit 34 decoding, be input to RC oscillating circuit 12, control electronic switch K1, K2 ..., the keying of KN-1.At this moment, measure the RC oscillating circuit frequency of oscillation of 12 this moments, by one group of pre-adjustment value of pre-adjustment value register 31, select corresponding adjusted value then, make the frequency of oscillation of RC oscillating circuit 12 reach designing requirement by the design test passage.Then, Ci Shi pre-adjustment value is stored in the programming value register 32.Programming value register 32 can be a disposable programmable read-only memory, after being burnt to this pre-adjustment value in the programming value register 32, select the control signal Ctl that the input of programming value register 32 is selected in a selector 33 inputs to two, two select a selector 33 offers decoding circuit 34 to the programming value of programming value register 32, to regulate the output frequency of RC oscillating circuit.

The signal that above-mentioned register and decoding circuit are handled can be the digital signal of one 7 bit, and the digital signal of 7 bits can realize 128 grades selection control.Certainly, according to actual needs, also can increase or reduce bit number.

In sum, the present invention has simplified the structure and the peripheral circuit of chip by at the inner built-in high-precision oscillating circuit of integrated circuit (IC) chip, has reduced cost, has saved the pin position of chip, for further expanding of chip functions provides convenience.Simultaneously,, make built-in RC oscillating circuit can provide high-precision frequency of oscillation equally, satisfy the high request of chip oscillation signal frequency by technological means such as regulating circuits.

Claims

1. the integrated circuit (IC) chip of a built-in frequency oscillator, this chip comprises:

One internal circuit is used to realize the basic function of chip; With

Described internal oscillator circuit comprises: