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.
Additional Features
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
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.
Additional Features
- 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
