Power output short circuit protection circuit and method

Abstract

The invention discloses a power output short circuit protection circuit and method. The power output short circuit protection circuit comprises a driving circuit, a time-delay circuit and an MOS on-signal generating circuit, wherein the power of the driving circuit, the power of the time-delay circuit and the power of the MOS on-signal generating circuit are supplied by a power source. The MOS on-signal generating circuit generates an MOS on-signal and transmits the MOS on-signal to the time-delay circuit, the MOS on-signal is delayed by the time-delay circuit to be transmitted to the driving circuit, and the driving circuit drives an MOS switch in a power output circuit to be on according to the MOS on-signal. In this way, when a power output short circuit occurs, the power of the driving circuit is off, the MOS switch is naturally driven to be off, and a short-circuit loop is opened; in addition, after the power is on, as the MOS switch is driven in a delayed mode to be on, the output power of the power source is much smaller than the rated power of the power source, and the power output short circuit is prevented. The scheme is simple, practicable and easy to implement, the running performance is stable and reliable, and the power output short circuit can be prevented with low cost and low power losses.

Description

technical field [0001] The invention belongs to the field of circuit control, in particular, the invention relates to the output short-circuit protection technology of power sources such as lithium batteries, photovoltaic batteries and stabilized voltage sources. Background technique [0002] In applications with power sources such as lithium batteries, photovoltaic cells, and voltage regulators, a MOS switch is usually connected in series at the output end, and the output of the power supply is controlled by controlling the conduction of the MOS switch. [0003] see figure 1 , the common power supply output short-circuit protection method is to connect sampling resistors in series in the output circuit to detect the output current and output voltage, the control circuit judges whether the output is short-circuited through the current signal and the voltage signal, and drives the MOS switch when the output short-circuit occurs Disconnect to achieve the purpose of protecting...

AI Technical Summary

Problems solved by technology

[0004] In practical applications, the detection of current and voltage signals results in additional cost increases; series resistors also generate additional power loss

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