Fixed-frequency quasi-sliding mode controller applicable to single-inductance double-output buck converter

Abstract

The invention discloses a fixed-frequency quasi-sliding mode controller applicable to a single-inductance double-output buck converter. The fixed-frequency quasi-sliding mode controller comprises an equivalent follow current duty ratio detector, a fixed-frequency quasi-sliding mode equivalent control signal generator, a first comparator comp1 and a dynamic follow current generation circuit, wherein the equivalent follow current duty ratio detector is used for detecting an equivalent follow current duty ratio signal of inductance current; the fixed-frequency quasi-sliding mode equivalent control signal generator is used for outputting a fixed-frequency quasi-sliding mode equivalent control signal; the first comparator comp1 is used for outputting a control signal D1 and a control signal D2 of a synchronous sequential tube S1 and a synchronous sequential tube S2; and the dynamic follow current generation circuit is used for generating a control signal of a follow current tube S3 and selecting follow current at the next moment according to an inductance current follow current duty ratio signal at the current moment. Compared with the controller in the prior art, the fixed-frequency quasi-sliding mode controller has the advantages that the problems of over-high voltage cross-modulation and low transient response speed in the single-inductance double-output buck converter can be solved, and the load working range of the single-inductance double-output buck converter can be greatly expanded on the premise of keeping high efficiency of a system and quick response.

Description

technical field [0001] The invention relates to a single-inductance double-output step-down converter, in particular to a fixed-frequency quasi-sliding mode controller applied to a single-inductance double-output step-down converter. Background technique [0002] Because the single-inductor dual-output buck converter can generate two different voltage outputs with only one off-chip inductor, which reduces the size of the power supply module, it is widely favored in portable product applications; without affecting Under the premise of system efficiency, improving the response speed of the system and reducing the intermodulation between the two output voltages have become the core research part of this field, which directly determines the performance of the entire switching power supply module. Single-inductor dual-output buck converter is a control system with fast response and small intermodulation. [0003] The two outputs of the single-inductor dual-output buck converter ...

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Problems solved by technology

[0008] The invention provides a fixed-frequency quasi-sliding mode controller applied to a single-inductance double-output step-down converter. Compared with the prior art voltage feedback controller and peak current controller, it can further overcome the single-inductance double-output drop Problems of excessive voltage intermodulation and poor transient response speed in voltage converters

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