Multi-output boost circuit

Abstract

The invention relates to a multi-output boosted circuit. The circuit comprises a plurality of voltage comparators, a duty ratio signal generator, a control logic circuit and an output circuit, whereina reference voltage is input into the first input end of each voltage comparator, a feedback voltage is input into the second input end, and comparison signals are output from the output end. The duty ratio signal generator generates a duty ratio signal. The control logic circuit inputs the comparison signal and the duty ratio signal and determines the form of the driving signal according to thecomparison signal. The driving signal includes a charging signal and a plurality of freewheeling signals, wherein the charging signal and the plurality of freewheeling signals are generated accordingto the duty cycle signal. The output circuit includes an inductor, a charging switch, a plurality of freewheeling switches, and a plurality of capacitors, wherein the inductor and the charging switchare connected between a power supply and the ground, each freewheeling switch is connected with the inductor and the corresponding capacitor, the charging switch inputs a charging signal, the freewheeling switch inputs a corresponding freewheeling signal, and the voltage on each capacitor is used as a feedback voltage.

Description

technical field [0001] The invention relates to a booster circuit, in particular to a multi-output booster circuit capable of outputting multiple voltages. Background technique [0002] In a system that requires multiple boost power supplies, using a single-inductor multi-output boost structure can effectively reduce the number of inductive components and reduce system cost. However, while obtaining the benefits of saving the number of external components, the control system inside the single-inductor multiple-output structure becomes more complicated. [0003] figure 1 It is a structural schematic diagram of a multi-output boost circuit in the prior art. refer to figure 1 As shown, the error amplifier 101 and the error amplifier 102 respectively amplify the errors of the multi-output voltage feedback signals V1, V2 and the reference voltage to generate VC voltages VC1 and VC2, which are used in the voltage feedback loop. The inductor current sampling and slope compensat...

AI Technical Summary

Problems solved by technology

[0008] The structure of the multi-output boost circuit of the prior art described above has the following disadvantages when applied in a low-power and low-load system: 1. In order to take into account the stability of the voltage feedback and current feedback loops, the circuit structure is complicated and the design is difficult. 2. There are many circuit modules, and large compensation resistors and capacitors are required, which occupy the chip area; 3. The loop structure is complex and uses more functional module circuits, which makes the circuit power consumption higher, which is not suitable for low-end power load system

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