The AT9919 is a PWM controller IC designed to drive high brightness LEDs using a buck topology. It operates from an input voltage of 4.5 to 40VDC and employs hysteretic controlwith a high-side current sense resistor to set the constant output current.The operating frequency range can be set by selecting the proper inductor. Operation at high switching frequency is possible since the hysteretic control maintains accuracy even at high frequencies. This permits the use of small inductors and capacitors minimizing space and cost in the overall system.LED brightness control is achieved with PWM dimming from an analog or PWM input signal. Unique PWM circuitry allows true constant color with a high dimming range. The dimming frequency is programmed using a single external capacitor.The AT9919 comes in a small, 8-Lead DFN package and is qualified for automotive LED lighting applications.

  Hysteretic control with high-side current sensing

  Wide input voltage range: 4.5 to 40V

  >90% Efficiency

  Typical ±5% LED current accuracy

  Up to 2.0MHz switching frequency

  Adjustable constant LED current

  Analog or PWM control signal for PWM dimming

  Over-temperature protection

  -40ºC to +125ºC operating temperature range

  AEC-Q100 compliant