Overvoltage protection device

摘要

An overvoltage protection device capable of protecting a power supply line and including in parallel a break-over diode, a controlled switch, and a circuit for controlling the switch.

主权项

1. An overvoltage protection device capable of protecting a power supply line, comprising:
a diode component including a break-over diode connected between first and second terminals of the power supply line, the diode component being configured to conduct in response to an overvoltage across the first and second terminals exceeding a break-over voltage of the break-over diode, an electronic switch in parallel with the diode component, and a control circuit coupled to the break-over diode and configured to close the electronic switch after the overvoltage is no longer across the first and second terminals, wherein the electronic switch is configured to cause the break-over diode to not conduct in response to the electronic switch being closed, wherein the control circuit comprises: a first comparator configured to compare a voltage on an anode of the diode component to a reference voltage; a second comparator configured to compare the voltage on the anode with a threshold substantially corresponding to a voltage across the diode when conducting; an AND gate having first and second inputs respectively coupled to outputs of the first and second comparators; and a buffer amplifier coupled between an output of the AND gate and a control terminal of the switch.