BUCK converter and input/output control circuit thereof

Abstract

The invention provides a BUCK converter and an input / output control circuit thereof. The input / output control circuit comprises a duty cycle logic control circuit and an inductor peak-valley value logic control circuit. The duty cycle logic control circuit comprises a first input end connected with a pulse width modulation comparator; a second input end connected with the inductor peak-valley value logic control circuit; a third input end connected with an on-time comparator; and a logic gate circuit comprising a first NOT gate, a first AND gate for carrying out logic and operation on the output of the first NOT gate and the output of the pulse width modulation comparator, a second NOT gate, a second AND gate for carrying out logic and operation on the second NOT gate and the output of theon-time comparator, and a first OR gate for carrying out logic and operation on the second AND gate and the output of the inductor peak-valley value logic control circuit. The BUCK converter has theadvantage of fast transient response; and when a load sends short circuit abnormity, inductor current can be stabilized and limited within the peak value and the valley value, thereby achieving a wide-range of input and output purpose.

Description

technical field [0001] The invention belongs to the technical field of power electronics, in particular to a BUCK converter and its input and output control circuit. Background technique [0002] Buck converter, also known as step-down converter, is a single-tube non-isolated DC converter whose output voltage is lower than the input voltage. At present, the BUCK converter based on the adaptive on-time (ACOT) control architecture, as an extension of the hysteretic control architecture, has a simple system structure, can achieve fast linear response and load response, and is basically only suitable for high input voltage and low output voltage It is rare to see the application of a wide range of input and output. For wide-range input and output applications, traditional fixed-frequency voltage mode control is mostly used, but the loop structure is more complicated, the loop stability compensation is also more complicated, and the transient response is slower. [0003] The la...

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Problems solved by technology

[0004] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a BUCK converter and its input and output control circuit, which is used to solve the problem that the BUCK converter in the prior art cannot effectively expand to a wide range of input and output. application, and cannot maximize the problem of quickly adjusting the output voltage when the load jumps from light load to heavy load

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