The A6271 is a DC-DC converter controller, providing a programmable constant-current output for driving high-power LEDs in series. The controller is based on a programmable fixed-frequency, peak current-mode control architecture. The DC-DC converter can be configured in a myriad of different switching configurations including boost, buck-boost, and buck (ground-referenced switch).
A6271使用外部逻辑电平MOSFET和最小额外的外部组件提供经济高效的解决方案。最大LED电流设定为单个外部检测电阻，可以使用电流参考输入（模拟控制）精确调制。通过PWMIN输入可以提供外部PWM调光，这也提供了关闭模式。作为替代方案，可以通过编程PWMIN和DR引脚来使用内部PWM调光电路。PWM方案控制PWMOUT输出，驱动与LED串串联连接的外部P沟道MOSFET。该MOSFET还用于在某些故障条件下隔离负载，包括输出短路到地。
The A6271 has been carefully designed to minimize electromagnetic emissions through distributed decoupling and an externally programmable frequency dither circuit configured for the EMI specification CISPR 25. It is also possible to program the fundamental switching frequency below 150 kHz where most EMI standards begin.
A6271拥有一套全面的集成保护功能，可保护IC，LED驱动器系统和LED串免线故障。固定输出过压保护确保了不可能在可编程输出过电压保护电路的单点故障下进行最大电压额定值。其他保护功能包括：LED过载（升压），输出欠压（降压或降压），输入电源（VIN）欠压，5 V稳压器（VREG）输出欠压，高侧供电（PWM PMOS）欠压，以及热保护。
These parts are in production but have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available.
Date of status change: December 14, 2017
Recommended Substitutions:A6271.-1
