Low-voltage-drop power supply circuit

Abstract

The invention belongs to a power supply circuit, and specifically relates to a low-voltage-drop power supply circuit. The circuit comprises a lithium battery module and a main power module. An outputend of the lithium battery module and an output end of the main power module are connected with a power supply end of an external circuit through a power switching circuit. The power switching circuitincludes a first switching circuit, a second switching circuit and a third switching circuit. The output end of the lithium battery module is connected with the first end of the first switching circuit, and the second end of the first switching circuit is connected with the second end of the second switching circuit and the third end of the third switching circuit. The first end of the second switching circuit is connected with the first end of the third switching circuit, the third end of the second switching circuit is connected with the second end of the third switching circuit, and the second end of the third switch circuit is also connected with the output of the main power module. The low-voltage-drop power supply circuit of the invention can automatically switch the power supply mode between the main power supply and the lithium battery power supply under different working conditions through a pure analog circuit.

Description

technical field [0001] The invention belongs to a power supply circuit, in particular to a low voltage drop power supply circuit. Background technique [0002] For some critical systems that require uninterrupted power supply and high reliability, such as communication equipment, monitoring systems, etc., in addition to the main power supply, it is often necessary to design a lithium battery circuit as a backup power supply, which is merged with the main power supply and provides external power supply together. Equipment power supply, in order to prevent the main power supply from power failure in an unexpected situation, which will affect the external power supply equipment. In the traditional power combination scheme, the voltage drop in the circuit is large. Under different working conditions, the power supply switching between the main power supply and the lithium battery power supply is mainly controlled by the external logic judgment circuit or the signal generated by ...

AI Technical Summary

Problems solved by technology

In the traditional power combination scheme, the voltage drop in the circuit is relatively large. Under different working conditions, the power supply switching between the main power supply and the lithium battery power supply is mainly controlled by the external logic judgment circuit or the signal generated by the controller to control the two power supplies. On and off, resulting in complex circuits, high cost, and more power loss, there are certain safety hazards for high-reliability systems

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