Time sharing multiplex control method for single-inductance double-output switching power supply and circuit thereof

Abstract

The invention relates to a time sharing multiplex control method for a single-inductance double-output switching power supply and a circuit thereof. Two DC-DC (direct current) converters are integrated in one chip to generate outputs of two voltages; two output branch circuits share one inductance; the time sharing multiplex control method is adopted; a time sharing conduction switch is arranged at an output end of each output branch circuit; one clock period is divided into a plurality of units; in each clock period divided unit, one path of output is separately controlled; the voltages of the two paths of outputs are respectively compared with a reference voltage to generate duty cycle pulse signals for controlling a primary loop and a secondary loop; then the duty cycle pulse signals are input into a gating signal generating module to generate two gating signals; and the two gating signals are input into a driving module to generate gating signals of a primary switch and a secondary switch, so that two paths of outputs without cross influence in a continuous conduction mode are realized and the aims of outputting two paths of stable voltages and regulating the size of a load current are fulfilled.

Description

technical field [0001] The invention relates to a power converter, in particular to a time-division multiplexing control method and circuit of a single-inductance double-output switching power supply. Background technique [0002] With the development of electronic equipment and the increase of complexity, there are more and more unit modules inside the whole machine, and the power supply voltage and power supply requirements of different modules are often different. For example, the motherboard of a computer needs to provide power supply voltages of 3.3V, 5V, and 12V for different devices such as memory, hard disk, CPU, and graphics card. Another example is the current smart phone, except that the RF module requires low noise and high power supply voltage rejection ratio, and needs to be powered by LDO, most of the other modules use DC-DC switching power supply for efficiency reasons, and the power supply voltage ranges from 1.5V to 15V wait. It can be seen that the resea...

AI Technical Summary

Problems solved by technology

But this method mainly has three disadvantages: firstly, the pure resistive correction branch reduces the efficiency of the switching power supply; secondly, the correction cycle changes the switching period of the switching power supply; Must be equal or not much different

These shortcomings limit the application of the correction branch control method in SIMO switching power supply

Images