Power supply overcurrent and overvoltage protection

xxhhzz

Power supply overcurrent and overvoltage protection [Copy link]

I want to protect the power supply from voltage, undervoltage, surge, etc. Is there any reference design I can refer to? (Car power supply)

maychang

The power source of the vehicle power supply is the battery and generator on the vehicle. As long as it is not connected to the mains, it will not be over-voltage.

btty038

If the requirements are not high, you can use an op amp for comparison.

qiushenghua

The overvoltage and undervoltage here refer to the protection of the system itself when the input is overvoltage or undervoltage, or do you want to make a power output device and shut down the output to protect the lower-level devices when overvoltage or undervoltage occurs? It seems to be the previous situation. Generally, our practice is, first of all, the IC connected to VDD must have sufficient voltage resistance, otherwise the IC will be directly damaged and all protections will be meaningless. Then, the voltage is collected through the ADC of the MCU, and the enable of the Power IC is directly turned off when the voltage is overvoltage or undervoltage. When the voltage is undervoltage, the MCU enters the sleep mode by itself. When overvoltage occurs, it can temporarily not enter sleep mode and wait for the voltage to drop before resuming work. Since overshoot may occur when the circuit is connected, in order to avoid false protection caused by overshoot, all overvoltage and undervoltage protection must be determined for a certain duration. Only when the overvoltage or undervoltage continues (usually a few ms to a few hundred ms) can the corresponding protection measures be implemented.