Diodes AL3158三路1x(2x)电荷泵白光LED驱动方案

Diodes 公司的AL3158 是高效1x/2x电荷泵白光LED驱动器,DC/DC转换器采用双模式负载开关1x 或2x,VIN电压范围从2.7V到5.5V,最大电源效率高达93%,每路LED电流20mA,路间电流匹配1%,内置了VOUT短路和LED短路保护功能,主要用在手机白光LED背光和指示器,PDA以及以电池为能源的电话主从屏幕白光LED背光.本文介绍了AL3158主要特性,功能方框图以及典型应用电路.

HIGH EFFICIENCY 1x/2x CHARGE PUMP FOR WHITE LED APPLICATIONS

The AL3158 is a low noise, constant frequency charge pump DC/DC converter that uses a Dual mode load switch (1x), and (2x) conversion for white LED applications. The AL3158 is capable of driving three groups of three LED channels at 20mA from a 2.7V to 5.5V input. The current sinks may be operated using three simple PWM dimming inputs individually or in parallel for driving highercurrent LEDs. Low external part counts (one 1μF flying capacitor and two 2.2μF capacitors at VIN and VOUT) make this part ideally suited for small, battery-powered applications.

AL3158 PWM dimming inputs are used to enable, disable device and dimming LED current with a fixed default current settings at 20mA or other factory programming options available.
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