High-precision relaxation oscillator capable of being trimmed and regulated

Abstract

The invention discloses a high-precision relaxation oscillator capable of being trimmed and regulated. The high-precision relaxation oscillator comprises an oscillation generator, a high-precision current bias generator, a voltage regulator and a driving and output part, wherein the high-precision current bias generator provides the bias for a constant current source in the oscillation generator, the voltage regulator generates two threshold levels for a comparator in the oscillation generator, and the oscillation generator utilizes capacitor charging and discharging to generate oscillation waveform to be provided for the driving and output part. The high-precision relaxation oscillator has the positive effects that through the realization of the high-precision bias current and the trimming and regulation of a register of the comparison threshold levels, the process deviation and the oscillator frequency change during the power supply voltage or environment temperature change can be reduced, and the value after the frequency modification can meet the designed precision requirements.

Description

technical field

[0001] The invention relates to the field of integrated circuits, in particular to an adjustable high-precision relaxation oscillator, which can be applied to the reference clock of the SOC system on chip. Background technique

[0002] Oscillators are an essential part of many electronic systems. The relaxation oscillator, also known as the charge-discharge oscillator, works by alternately charging and discharging the capacitor between two threshold levels that have been set in the circuit. In this way, the circuit first relaxes one quasi-stable state until it reaches a certain threshold level position; then, the circuit switches and relaxes to another quasi-stable state until it reaches another threshold and then switches back to the first quasi-stable state . The process continues in this manner.

[0003] The basic topology of a relaxation oscillator is as figure 1 shown. Among them, S1 represents a control switch, and COMP represents a comparator incl...

Examples

Embodiment Construction

[0020] A trimmable high-precision relaxation oscillator, such as figure 2 As shown, it includes an oscillation generator 100 , a high-precision current bias generator 200 , a voltage regulator 300 , and a drive and output part 400 . Among them: the oscillation generator 100 generates an oscillation waveform by charging and discharging a capacitor, the high-precision current bias generator 200 provides a bias for the constant current source in the oscillation generator, the voltage regulator 300 generates two threshold levels of the comparator, and the register Configuration modification is also included in this part, and the driving and output part 400 improves the driving capability of the oscillator waveform through an inverter chain and outputs the waveform.

[0021] The oscillation generator 100 includes four PMOS transistors 110, 111, 112, 113 (namely M1, M2, M3, M4); four NMOS transistors 120, 121, 122, 123 (namely M5, M6, M7, M8); Charge and discharge capacitor 130 (i...

technical field

[0001] The invention relates to the field of integrated circuits, in particular to an adjustable high-precision relaxation oscillator, which can be applied to the reference clock of the SOC system on chip. Background technique

[0002] Oscillators are an essential part of many electronic systems. The relaxation oscillator, also known as the charge-discharge oscillator, works by alternately charging and discharging the capacitor between two threshold levels that have been set in the circuit. In this way, the circuit first relaxes one quasi-stable state until it reaches a certain threshold level position; then, the circuit switches and relaxes to another quasi-stable state until it reaches another threshold and then switches back to the first quasi-stable state . The process continues in this manner.

[0003] The basic topology of a relaxation oscillator is as figure 1 shown. Among them, S1 represents a control switch, and COMP represents a comparator incl...

Examples

Embodiment Construction

[0020] A trimmable high-precision relaxation oscillator, such as figure 2 As shown, it includes an oscillation generator 100 , a high-precision current bias generator 200 , a voltage regulator 300 , and a drive and output part 400 . Among them: the oscillation generator 100 generates an oscillation waveform by charging and discharging a capacitor, the high-precision current bias generator 200 provides a bias for the constant current source in the oscillation generator, the voltage regulator 300 generates two threshold levels of the comparator, and the register Configuration modification is also included in this part, and the driving and output part 400 improves the driving capability of the oscillator waveform through an inverter chain and outputs the waveform.

[0021] The oscillation generator 100 includes four PMOS transistors 110, 111, 112, 113 (namely M1, M2, M3, M4); four NMOS transistors 120, 121, 122, 123 (namely M5, M6, M7, M8); Charge and discharge capacitor 130 (i...

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