AT9919

AT9919 Hysteretic Buck High-Brightness LED Driver with High-Side Current Sensing Features AEC-Q100 Qualified Hysteretic Control with High-side Current Sensing Wide Input Voltage Range: 4.5V to 40V >90% Efficiency Typical ±5% LED Current Accuracy Up to 2 MHz Switching Frequency Adjustable Constant LED Current Analog or Pulse-Width Modulation (PWM) Control Signal for PWM Dimming Overtemperature Protection –40ºC to +125ºC Operating Temperature Range Applications LED Lighting Applications Automotive Applications General Description 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 VDC to 40 VDC and employs hysteretic control with 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. AT9919 comes in a small, 8-Lead WDFN package and is qualified for LED lighting applications. AT9919 passes the automotive AEC-Q100 reliability test...