Short circuit detection circuit and control method thereof

摘要

A short circuit detection circuit for detecting short circuit of a series of light-emitting diodes includes a constant current source, a rectifier, and a detector. The constant circuit source provides a setting current. The rectifier is coupled between a feedback node and the constant current source. The feedback node is coupled to a terminal of the series of light-emitting diodes. When a feedback voltage of the feedback node exceeds a short reference voltage, the rectifier allows the setting current sinks the feedback node. The detector detects the feedback voltage of the feedback node. When the feedback voltage exceeds a predetermined value, short-circuit protection is triggered to make the series of light-emitting diodes be turned off.

主权项

1. A short circuit detection circuit for detecting short circuit of a series of light-emitting diodes, the short circuit detection circuit comprising:
a constant current source for providing setting current; a rectifier coupled between a feedback terminal and the constant current source, wherein the feedback terminal is coupled to a terminal of the series of light-emitting diodes for making the setting current sink the feedback terminal when a feedback voltage of the feedback terminal exceeds a short circuit reference voltage; and a detector for detecting the feedback voltage of the feedback terminal, and triggering short-circuit protection to make the series of light-emitting diodes be turned off when the feedback voltage is higher than a predetermined value.