The invention relates to the technical field of automobile lighting, and discloses a constant-current
driving circuit with LED open circuit and
short circuit detection and high-temperature
derating, which comprises a 5V constant-
voltage module connected with an external power supply and used for supplying power to the whole circuit
system; according to the constant-current
driving circuit with the LED open circuit and
short circuit detection and high-temperature
derating functions, an LED open circuit /
short circuit detection circuit composed of a digital
triode and a T9 is adopted, the working state of each LED string is collected in real time, and when any LED string breaks down, the LED string is connected with the NTC high-temperature
derating module circuit, and the NTC high-temperature derating module circuit is connected with the 5V constant-
voltage module. The corresponding triodes are conducted and the level of related pins of a
comparator of the
chip U1 is lowered, so that a feed back
signal fed back to a vehicle body controller is changed from a high level to a low level, and meanwhile, the circuit can flexibly adjust the number of the power triodes and the number of the triodes in the detection circuit according to the number of the LED strings; therefore, the problems that in the prior art, the
detection threshold value of an integrated
chip scheme is fixed and cannot be flexibly adjusted, and a discrete component scheme is prone to interference and misjudgment, and LED open circuit and short circuit detection precision and reliability are insufficient are solved.