Step-Down Power Converter with Wide-Voltage Input

Abstract

The invention discloses a wide-voltage input step-down power converter, which includes a control circuit of a switch tube, and the control circuit of the switch tube adopts a logic circuit, including a voltage feedback control circuit, a current feedback control circuit and an AND gate, wherein, The voltage feedback control circuit includes a first hysteresis comparator, and the negative terminal of the first hysteresis comparator is a feedback voltage input terminal. The positive terminal is the first reference input terminal, and the output terminal is connected to the first input terminal of the AND gate; the current feedback control circuit includes a second hysteresis comparator, the negative terminal of the second hysteresis comparator is the output current sampling terminal, and the second The positive terminal of the two-hysteresis comparator is the second reference input terminal, and the output terminal is connected to the second input terminal of the AND gate; the output terminal of the AND gate is used as the output terminal of the control circuit of the power switch tube, and is used for the drive terminal of the AND switch tube connect. The present invention adopts the control scheme of hysteresis voltage and hysteresis current to reduce useless loss.

Description

technical field [0001] The invention relates to the field of low power consumption power supply, in particular to a step-down power converter with wide-voltage input and a control method for a switch tube thereof. Background technique [0002] In the power control solution industry at this stage, the wide-voltage (120-374VDC input voltage range) step-down solution is generally a flyback solution, which has the characteristics of high cost and large size. At the same time, the light-load power consumption is high, which wastes energy and resources for the entire society larger. At this stage, the zero standby power supply adopts control schemes such as COT (the English abbreviation of constant on-time, Chinese translation is constant on-time) scheme, floating control scheme, light load timing detection output voltage and other control strategies. The application of wide voltage range cannot be achieved, and at the same time, the output voltage performance is sacrificed, so t...

AI Technical Summary

Problems solved by technology

[0002] In the power control solution industry at this stage, the wide-voltage (120-374VDC input voltage range) step-down solution is generally a flyback solution, which has the characteristics of high cost and large size. At the same time, the light-load power consumption is high, which wastes energy and resources for the entire society larger

At this stage, the zero standby power supply adopts control schemes such as COT (the English abbreviation of constant on-time, Chinese translation is constant on-time) scheme, floating control scheme, light load timing detection output voltage and other control strategies. It cannot be applied in a wide voltage range, while sacrificing the output voltage performance, so that the power supply function and performance are limited

Among them, the output voltage of the floating control scheme is indirectly sampled, and the light-load timing detection output voltage has a blind area of ​​output voltage feedback for a period of time. Both of them cannot meet the application requirements of the full range of input voltage under dynamic conditions, and power supply products cannot be used in wide-voltage applications. , the current COT control scheme combines the minimum on-time with valley detection, the minimum frequency is greater than 100Hz, the minimum frequency of other schemes ranges from greater than 100Hz-1000HZ, the power consumption is still too large, and the control circuit is complicated

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