Pulse width modulation (PWM) hysteresis control method based on ripple

Abstract

The invention relates to a pulse width modulation (PWM) hysteresis control method based on a ripple. On the basis of traditional hysteresis control, with the help of the feedback of an introduction of the inductor ripple current and the capacity parasitic resistance ripple voltage, a transient response of the hysteresis control is greatly improved and anti-load disturbance capability and dynamic characteristics are better. According to the PWM hysteresis control method based on the ripple, due to the fact that only a hysteresis comparator and a feedback regulation resistor are needed, the number of components of a control circuit is greatly reduced, and cost and size are greatly reduced. Moreover, due to the fact that an error amplifier is not used, when phase delay caused by a compensation circuit is eliminated, the dynamic characteristics of a control circuit are also effectively improved. The PWM hysteresis control method based on the ripple has the advantages of being fast in transient response of output voltage, low in overshoot, and short in convergence time.

Description

technical field [0001] The invention relates to a DC switching power supply control method, in particular to a ripple-based PWM hysteresis control method. Background technique [0002] With the rapid development of communication technology, the volume of DC switching converters is getting smaller and smaller, the efficiency is getting higher and higher, the power density is getting higher and higher, and the requirements for dynamic load performance are becoming more and more stringent. Especially in low-voltage and high-current applications, how to design a power supply that meets the requirements is a major challenge in the field of power electronics. These challenges put forward higher requirements for the voltage regulator module (Voltage Regulator Module, VRM) of the DC switching converter: (1) fast dynamic response to the load (2) high voltage regulation accuracy (3) high power conversion efficiency. These pose new challenges to the control technology of the DC conver...

AI Technical Summary

Problems solved by technology

However, when this control method has a sudden change in the load, due to the delay lag caused by the compensation circuit of the voltage error amplifier in the control circuit, it not only causes its transient response to be slow, but also reduces its dynamic characteristics.

Moreover, the compensation circuit of the voltage error amplifier is more complicated to design and debug

These problems have brought great difficulties to the design of the control circuit.

[0003] In the traditional PWM voltage control method, the triangular carrier generation circuit, operational amplifier and corresponding compensation circuit are used, which increase the size of the conversion circuit and make it difficult to achieve miniaturization and light weight; the error characteristics of the operational amplifier seriously affect the control circuit. performance

Make the designer spend a lot of time and manpower and material resources when solving the stability problem of the operational amplifier; in the traditional PWM voltage control method, adjusting the phase compensation circuit is to improve the load variation characteristics through the gain and bandwidth of the error amplifier. These designs are relatively Complicated and not easy to do; the traditional hysteresis PWM control method does not use the idea of ​​inductor current ripple and capacitor parasitic resistance ripple voltage to lead to feedback

The performance of the DC conversion circuit cannot be optimized

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