Secondary-ring control system for single-inductor multiple-output switch power converter

Abstract

A secondary-ring control system for a single-inductor multiple-output switch power converter is disclosed. In the secondary-ring control system, a hysteresis comparator of upper-threshold voltage VH and lower-threshold voltage VL is employed in each secondary-ring control branch to replace a conventional secondary-ring error amplifier and a secondary-ring PWM comparator. The input of the hysteresis comparator in each secondary-ring control branch is n-1 differential-mode voltage V<fbi> (i=1, 2... n-1) respectively, and the V<fbi> is compared with the upper-threshold voltage VH and the lower-threshold voltage VL. When the V<fbi> is lower than the lower-threshold voltage VL, the duty ratio control signal PWM is of high level, and secondary power switch tube in corresponding output branch is turned on. When the V<fbi> is higher than the high-threshold voltage VH, the duty ratio control signal PWM is of low level, and secondary power switch tube in corresponding output branch is turned off. In this way, secondary duty ratio signals can be rapidly controlled through hysteresis comparators.

Description

technical field [0001] The invention relates to a single-inductance multi-output switching power supply converter, in particular to a secondary loop control system of the single-inductance multi-output switching power supply converter, and belongs to the field of microelectronics. Background technique [0002] Single-Inductor Multiple-output (SIMO) switching power converter is a new type of multi-output switching converter structure. It uses the time-sharing principle of each output branch to independently control multiple power supplies with only one inductor. The output is suitable for power supply of multi-value voltage system. Each output branch shares an inductance and works in time-sharing, which greatly reduces the number of inductances required by the circuit. Therefore, while realizing the independent and precise control of each output branch, the size of the converter system is greatly reduced. However, with the continuous development of battery-charging portable ...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a secondary loop control system of a single-inductance multi-output switching power supply converter. In order to improve the transient response, a hysteresis comparator is used in the secondary loop control system to generate a PWM duty cycle signal to realize the control of the secondary switch duty cycle. The signal is controlled quickly and accurately, which solves the problem of large output ripple caused by slow load transient response

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