BP1638CJ is a three-channel dimmable LED linear constant current driver chip with a built-in 40V/200mA MOSFET. By adjusting the duty cycle of the input three-channel PWM signals, the current of the corresponding LED light source is adjusted to achieve the purpose of dimming. BP1638CJ supports PWM dimming signals and can be used with common dimming modules to achieve dimming functions. BP1638CJ has an over-temperature regulation function. When the LED current is too large and causes the chip temperature to be too high, the output current will be reduced.