BUCK converter circuit

Abstract

The invention relates to a BUCK converter circuit, and belongs to the technical field of electronic products. The circuit comprises a DC input power supply which is used for providing an input power voltage; a BUCK circuit which carries out the conversion of the voltage of the DC input power supply; a bootstrap start circuit which is used for starting a controller during initial electric connection; a PWM controller which is used for generating a PWM control signal to drive a main circuit; a current feedback circuit which is used for sampling a current in the circuit and inputting the current into the PWM controller; a voltage feedback circuit which is used for sampling an output voltage and inputting the output voltage into the PWM controller. The circuit receives the sampled voltage and the sampled inductor current through the PWM controller, controls the on / off of a BUCK circuit, and enables a voltage outputted by the BUCK circuit to reach a preset stable value. Compared with a conventional BUCK converter, the circuit provided by the invention does not use an isolated optocoupler chip, does not use a reference voltage chip, and reduces the cost and size of the circuit to certain degree.

Description

technical field [0001] The invention belongs to the technical field of electronic products, and in particular relates to a design method for a split hatch door. Background technique [0002] In the fields of computer, communication, industrial control, instrumentation, medical equipment, etc., the application of switching power supply from high-voltage DC to low-voltage DC using BUCK (step-down) converter circuit design has been very extensive. Especially as the auxiliary power supply of some high-power power supplies, most of them use BUCK circuits. However, since the driving ground of the BUCK circuit is floating relative to the output ground, the voltage sampling needs to be transmitted to the circuit control chip through a combination of an isolated optocoupler and a voltage reference in the prior art. [0003] Such as figure 1 The existing BUCK converter circuit shown includes: a DC input power supply is used to provide an input power supply voltage; a BUCK circuit is...

AI Technical Summary

Problems solved by technology

[0003] like figure 1 The existing BUCK converter circuit shown includes: a DC input power supply is used to provide an input power supply voltage; a BUCK circuit is used to convert the input power supply voltage; a bootstrap startup circuit is used to start the controller when initially powered on; PWM control The circuit is used to generate the PWM drive voltage; the current feedback circuit is used to sample the current in the circuit and send it to the PWM controller; the voltage feedback circuit is used to sample the output voltage and send it to the PWM controller; however, the existing The current voltage feedback circuit is composed of isolated optocoupler and voltage reference, but the main disadvantage of this form of voltage feedback circuit is that due to the use of isolated optocoupler and voltage reference, the structure is complicated and the cost is high

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