Protection circuit of multi-stage DC conversion circuit

Abstract

The invention discloses a protection circuit of a multi-stage DC conversion circuit. The protection circuit at least comprises a primary DC conversion circuit and a secondary DC conversion circuit, wherein an output end of the primary DC conversion circuit is connected with an input end of the secondary DC conversion circuit through a first inductor, the protection circuit also comprises a first switching circuit, a first frequency selection circuit and a first trigger, an input end of the primary DC conversion circuit is connected with an output end of a power adaptor through the first switching circuit, an input end of the first frequency selection circuit is connected with an output end of the secondary DC conversion circuit, an output end of the first frequency selection circuit is connected with two input ends of the first trigger separately, and an output end of the first trigger is connected with a control end of the first switching circuit. The protection circuit is not high in technical realization difficulty and not high in cost, the function of mutual protection of each stage of DC conversion circuit can be achieved, the safety of the circuit board where the DC conversion circuit is located is ensured, and the reasonable control of the overall cost is also ensured.

Description

technical field [0001] The invention relates to a protection circuit for a power supply circuit, in particular to a protection circuit for a multi-stage DC conversion circuit. Background technique [0002] Most of the DC-DC chips on the current TV core board work independently, such as: 5V to 3V, 3V to 1.8V, 1.8V to 1V, but when the subsequent conversion chip (such as 1.8V to 1V) is damaged, the upper-level DC-DC chip may still be working, which will cause damage to the upper-level DC-DC or DC adapter, and then cause serious accidents. Most of the current solutions use integrated digital power supplies chips, but digital power chips are expensive, more than ten times the price of ordinary DC-DC. They are generally used in products such as pads that require a small core board area. For TV core boards with sufficient area, It will increase the cost of the product, waste the area of ​​the core board, and cause the infeasibility of mass production. Contents of the invention ...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem that the existing multi-stage DC conversion circuit lacks a protection mechanism when it is working, and when a DC conversion circuit of one stage fails, it may cause damage to the conversion circuit or DC adapter of other stages, a multi-stage DC conversion circuit is proposed. circuit protection circuit, which can solve the above problems

Images