The AT9919 is a hysteric, buck, and high brightness LED driver with high-side current sensing. It is basically a PWM controller which uses buck topology to drive LEDs. It operates from an input voltage of 4.5 to 40VDC at a temperature of -40ºC to +125ºC. 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.
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