
Status: In Production
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 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. The AT9919 comes in a small, 8-Lead DFN package and is qualified for automotive LED lighting applications.
The AT9919BDB1 demoboard is a high current LED driver designed to drive one LED at 1.0A from a 9.0 - 16VDC input. The demoboard uses an AT9919 hysteretic buck LED driver IC. The AT9919DB1 includes two PWM dimming modes. The analog control of the PWM dimming mode allows the user to dim the LED using a 0 - 2.0V analog signal applied between the ADIM and GND pins (0V gives 0% and 2.0V gives 100%). In...
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