AT9919中文资料Hysteretic, Buck, High Brightness LED Driver w/ High-Side Current Sensing数据手册Microchip规格书

描述 Description

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.

特性 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

简介

AT9919属于集成电路（IC）的LED驱动器。由制造生产的AT9919LED 驱动器器件属于 LED 驱动器电源管理集成电路 (PMIC) 系列，可通过标称固定电压的电源为负载（通常为发光二极管）提供电流，并且电流可控。它与用于电压调节的类似产品的主要区别在于，这类器件提供较低的反馈电压（以提高系统能效），而且通常可对器件工作点进行外部控制，可在照明应用中用于实现调光功能。