Output over-current and short-circuit protection circuit and electronic equipment

Abstract

The invention provides an output over-current and short-circuit protection circuit, which comprises a driving circuit, an MOS transistor and a protection circuit, and is characterized in that the protection circuit comprises a first triode and a sampling resistor, the driving circuit is connected with a grid electrode of the MOS transistor, a drain electrode of the MOS transistor is connected with a load, a source electrode of the MOS transistor is used for being connected to a power supply, the driving circuit is used for being connected to an IO interface of a controller, an emitting electrode of the first triode is connected with the source electrode of the MOS transistor, a base electrode of the first triode, the sampling resistor and the drain electrode of the MOS transistor are sequentially connected, and a collecting electrode of the first triode is connected with the driving circuit. The MOS transistor is adopted to act as an electronic switch, the triode and the sampling resistor form the protection circuit, and the source electrode and the drain electrode of the MOS transistor are directly connected with the protection circuit in parallel. The output over-current and short-circuit protection circuit has the advantages of low cost, high response speed, high reliability and low power consumption. The invention further relates to electronic equipment, which comprises a load and the output over-current and short-circuit protection circuit, wherein the load is connected with the output over-current and short-circuit protection circuit.

Description

technical field [0001] The invention relates to the technical field of circuit protection, in particular to an output overcurrent and short circuit protection circuit and an electronic device. Background technique [0002] In some security control systems, it is sometimes necessary to connect some external devices, such as smoke sensors, weather sensors, temperature sensors, sound and light alarms, cameras, etc. This will inevitably involve the power supply of peripherals, and it is multi-channel power supply. The power supply of such peripherals is usually provided by the system controller with multiple power supply interfaces exposed to the outside, and users can connect these peripherals by themselves through plugs and cables. If a certain peripheral fails, or the user accidentally short-circuits the power supply output when connecting the peripheral, and there is no over-current and short-circuit protection circuit in the controller, it is likely to cause damage to the ...

AI Technical Summary

Problems solved by technology

The relay is a mechanical switch. It takes at least tens of milliseconds from current detection and sampling to control its action to close. The response time is too long, and such a long response time may cause damage to the controller power supply and peripherals.

[0007] 3. Short life

When the relay is under load, the life of repeated switching is only about tens of thousands of times, which is a serious problem for equipment that requires trouble-free operation for three years, five years or even longer.

[0008] 4. High power consumption

When the relay is closed, it needs a certain holding current, which will increase the power consumption; in addition, the sampling resistor connected in series, the current will all flow through the sampling resistor, which will also increase the additional power consumption of the system

[0009] 5. Inflexible control

[0011] 1. High power consumption

It is also a series sampling resistor, which will increase the extra power consumption of the system

[0012] 2. Inflexible control

Images