DC-DC power supply compensation control circuit based on voltage-controlled delay line

Abstract

The invention discloses a DCDC power supply compensation control circuit based on a voltage-controlled delay line, which is divided into a compensation circuit and a delay line, a voltage-controlled output point is connected with the control end of the delay line, and the voltage-controlled output point is the output position of feedback voltage after passing through the compensation circuit. An external interface of the delay line comprises an external clock signal input end, a delay signal output end and a control end, the input end of the delay line is connected with a clock signal, and thefunction of converting voltage control into time control is achieved through the delay line. Meanwhile, a traditional Type III circuit compensation network serves as a voltage control part, control voltage is output, the delay size of a delay line is controlled, and it is ensured that the phase difference between delay line output and an external clock meets the control requirement, that is, theduty ratio meets the current state requirement, so stability is not affected on the premise that the wide output voltage range is achieved. Compared with a traditional control mode, the circuit has advantages of being simple in structure, high in efficiency, fast in transient response and the like.

Description

technical field [0001] The invention belongs to the technical field of integrated circuit design and specifically designs a DC-DC power supply compensation control circuit based on a voltage-controlled delay line. Background technique [0002] DC / DC converters are voltage converters that effectively output a fixed voltage after changing the input voltage. DC / DC converters are divided into three categories: step-up DC / DC converters, step-down DC / DC converters, and buck-boost type DC / DC converter. Three types of control can be used according to the requirements. The PWM control type has high efficiency and has good output voltage ripple and noise; the PFM control type has the characteristics of low power consumption at small loads; the PWM / PFM conversion type implements PFM control at small loads. And it will automatically switch to PWM control under heavy load. [0003] DC-DC converters are ubiquitous in power supply equipment. They are used to generate the supply voltage f...

AI Technical Summary

Problems solved by technology

[0005] At this stage, there are several problems in the design of high-frequency DC-DC converters: first, when the switching period is reduced to tens of nanoseconds or less, it may cause the PWM controller based on the slope comparator to fail, and additional measures are required to meet high-frequency requirements; secondly, larger comparator delays limit the duty cycle range, which not only affects transient response, but also limits the input / output operating voltage range

Reducing ripple requires high-precision ADC and DPWM, both of which consume a lot of power and increase the complexity of the design

[0006] The traditional solution uses a sawtooth wave and a control voltage to generate a drive signal by comparing it with a comparator, such as figure 1 As shown, when the output signal is disturbed, the feedback signal of the traditional scheme generates a control signal through the path of the compensator module and compares it with the reference signal to obtain a PWM signal. Due to the inherent delay of the comparator, the voltage conversion at a very high switching frequency range will be severely limited

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