A buck drive circuit, power chip and application thereof

Abstract

The invention discloses a BUCK drive circuit, a power supply chip and application thereof. The BUCK drive circuit comprises a power supply output module, a control module, an overcurrent protection module and an inductive discharge current detection module, wherein the power supply output module is used for adjusting input voltage so as to supply a power supply for a load; the control module is used for controlling the turning-on and turning-off of a power tube in the power supply output module; the overcurrent protection module is used for triggering the control module to turn off the power tube when the power supply output module is overcurrent; the inductive discharge current detection module is used for detecting inductive discharge current in a peripheral circuit matched with the drive circuit after the power tube is turned off and sending a feedback signal to the control module when the discharge current exceeds a preset current; the control module is further used for controlling the power tube to be maintained at a turn-off state when the feedback signal is received. The power tube is turned off to disconnect an inductive charge circuit when the inductive current is overcurrent, meanwhile a delay module in the prior art is omitted, an inductive discharge current detection module is added, and the inductive current of each period in an output short circuit is not overcurrent; and moreover, when the chip is manufactured, the feedback pin of the chip is saved, and the cost of the power supply chip is reduced.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a BUCK drive circuit and a power chip. Background technique [0002] Traditional BUCK structure power supply output short circuit protection Typical peripheral applications such as figure 1 shown. When the output Vout is short-circuited, it takes a long time to discharge the inductor L. If the inductor current is not set to a certain value in each switching cycle and the control chip is turned on again, it will cause the accumulation of inductor current. After several switching cycles, the current on the inductor will be very large, and the power in the control chip The pipe will be damaged, and in severe cases, the system will explode. [0003] The specific working principle of the traditional BUCK structure power supply output short-circuit protection is as follows: figure 2 It can be seen that the control chip detects the output terminal through the FB pin of th...

AI Technical Summary

Problems solved by technology

[0004] The disadvantages of this traditional control method are: 1) a control feedback pin is required, which increases the number of pins of the control chip and relatively increases the cost of the chip

2) When the output short-circuit error state occurs, the chip cannot respond immediately to take protective measures, and it is delayed for a period of time (to avoid the chip misjudging the short circuit), and during this delay time, the internal power tube of the chip may be damaged

Images