Short protection control circuits and related control methods

摘要

Short protection control circuits and related control methods are disclosed. A disclosed short protection control circuit is adapted for controlling a short protection mechanism providing short protection to several LED chains. The disclosed short protection control circuit has a detection circuit, a first logic circuit and a timer. Coupled to the LED chains, the detection circuit asserts an indication signal when one of the node voltages of the LED chains is lower than an under-current reference. When the indication signal is enabled, the first logic circuit starts blocking the short protection mechanism. The timer times to provide a result when the short protection mechanism is blocked. When the result indicates that the short protection mechanism has been blocked for at least a predetermined time period, the first logic circuit resumes the short protection mechanism.

主权项

1. A control method for use in controlling a short protection mechanism providing short protection to a plurality of light-emitting diode (LED) chains, wherein a plurality of driving currents flow through the LED chains, the control method comprising:
detecting whether at least one of the driving currents encounters an under-current event; blocking a short protection mechanism and resetting a timer when the under-current event is encountered, wherein the short protection mechanism provides short protection to the LED chains; and resuming the short protection mechanism after the short protection mechanism is blocked for at least a predetermined time period.