Low Power Oscillator Circuit Structure

Abstract

The present invention relates to a low-power oscillator circuit structure, which includes an external start-up circuit module, wherein the circuit structure further includes: a bias current generation circuit module, a sawtooth wave generation circuit module, a comparator and a trigger circuit module, a square A wave generation circuit module, the external startup circuit module is sequentially connected to the bias current generation circuit module, the sawtooth wave generation circuit module, the comparator and trigger circuit module, and the square wave generation circuit module. The low-power oscillator circuit structure adopting this structure can reduce power consumption, improve the characteristics of poor clock temperature drift in the prior art, facilitate adjustment of clock frequency, and have a wide range of applications.

Description

technical field [0001] The invention relates to the field of SOC chips, in particular to the field of low-frequency oscillating circuits built in the SOC chip, and specifically refers to a low-power oscillator circuit structure. Background technique [0002] SOC chips have the characteristics of powerful functions, flexible applications, and strong versatility, so they have been widely used in fire protection, security, and Internet of Things systems. In order to reduce the power consumption of the whole system, the SOC circuit is in sleep mode during standby, and the internal clock source only enables low-frequency clocks. The low-frequency clock scheme in the traditional SOC circuit often uses an external crystal oscillator. The advantage of this solution is that the frequency of the clock signal is stable and the anti-interference ability is strong; the disadvantage is that the crystal oscillator consumes a lot of power during operation, the application configuration is ...

AI Technical Summary

Problems solved by technology

[0003] The main problems of the existing low-frequency oscillator circuit are: only one or two performance indicators can be satisfied, the temperature drift is poor, and the adjustment method is relatively simple. If the oscillator needs to have multiple operating frequencies, it is not convenient and not enough to implement. Comprehensive, which brings great limitations to system applications

However, the disadvantage of this circuit is that the temperature coefficient of the capacitor charging and discharging current is greatly affected by the temperature coefficient of the threshold voltage of the MOS tube itself, which will cause a large temperature drift in the frequency of the oscillator.

therefore figure 1 The circuit cannot be used in systems that have certain requirements for clock temperature drift

[0006] There are following technical problems in this technical solution, figure 1 In the triangular wave generation circuit module in the circuit, the temperature drift of the capacitor charging and discharging current is strongly related to the temperature drift of the threshold voltage of the MOS tube, so the generated triangular wave has different rising / falling slopes at different temperatures, and finally passes the judgment of the comparator and the trigger The clock signal generated after triggering also has a large temperature coefficient; adjusting the clock frequency is mainly by adjusting the capacitor in the triangular wave generation module, and the adjustment method is relatively simple

If the oscillator is required to have multiple operating frequencies, it is not convenient to implement

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