The APM80950 and APM80951 are complete synchronous buck switching regulator modules that provides constant current output to drive high-power LEDs designed for industrial applications. 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-by cycle, controlled on-time method. Output current is user-selectable by an external current sense resistor. Output voltage automatically adjusts to the LED string voltage, ensuring the optimal system efficiency.
LED dimming is accomplished by a direct logic input pulse-width 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. 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 APM80950/1 are provided in a compact, thermally enhanced QFN-32 package with wettable flanks for easy integration.
