Oscillator system

Abstract

An oscillator system comprises the components of an operational amplifier which works in a sub-threshold region, wherein two input ends are respectively connected with a first end of a reference resistor and a first end of a switch capacitor circuit, an output end of the operational amplifier outputs first voltage, the reference resistor and the switch capacitor circuit are connected with one pathof reference current; a first capacitor of which the positive end is connected with the output end of the operational amplifier, and the negative end is grounded; a periodical signal module which converts a first voltage DC component to a periodical signal and outputs a first periodical signal after halving of the periodical signal and converts a second periodical signal after halving of the periodical signal to a third periodical signal and a fourth periodical signal that have opposite phases and are not stacked; and the switch capacitor circuit which comprises a second capacitor and controls charging and discharging of a second capacitor according to the third periodical signal and the fourth periodical signal, wherein the operational amplifier, the periodical signal module and the switch capacitor circuit form a negative feedback loop, and output frequency stability is ensured. Furthermore the operational amplifier works in the sub-threshold region and ultralow power consumption ofthe oscillator system is realized.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to an oscillator system. Background technique [0002] In the ultra-low power consumption micro control unit MCU chip, a clock with low power consumption, high power supply voltage and temperature stability is usually required to realize the timing function required by the system. [0003] Conventional RC oscillator circuits such as figure 1 As shown, including: comparator, current source, pulse generating circuit, clock generating circuit, reference resistor, capacitor and switch. One current flows through the reference resistor to generate a reference voltage Vref, which is connected to the negative phase terminal of the comparator, and the other current charges the capacitor to generate a voltage Vc. The positive terminal of the capacitor is connected to the positive phase terminal of the comparator, and the negative terminal is grounded. The traditional RC oscillator c...

AI Technical Summary

Problems solved by technology

[0004] The above RC oscillator uses a comparator structure, so it consumes a lot of power. In addition, the delay time of the comparator and pulse generating circuit is greatly affected by temperature, so the overall output frequency is greatly affected by temperature.

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