The APM80900 and APM80904 are complete synchronous buck switching regulator ClearPower modules that provide constant current output to drive high-power LEDs. They integrate both high-side and low-side N-channel switches, inductor, high frequency VIN and boot capacitors. A true average current is output using a cycle-bycycle, controlled on-time method.
Output current is user-selectable by an external current sense resistor. Output voltage automatically adjusts to the LED string voltage. This ensures the optimal system efficiency. LED dimming is accomplished by a direct logic input pulsewidth modulation (PWM) signal at the PWM pin while EN is enabled. Alternatively, applying a PWM signal at the EN pin while the PWM pin is high provides “chopped battery” PWM dimming for legacy control modules.
Expanding it's feature set, the APM80904 includes programmable internal dimming.
The analog dimming input (ADIM pin) can be used to calibrate the LED current or implement thermal foldback in conjunction with external NTC thermistor.
The APM80900 and APM80904 are automotive AEC-Q100 qualified and presented in a compact, thermally enhanced 4 mm × 6 mm × 2 mm QFN-32 package with wettable flanks.