AL3158设计的三路1x(2x)电荷泵白光LED驱动

本文介绍了AL3158主要特性,功能方框图以及典型应用电路.AL3158 是Diodes 公司的高效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.

AL3158主要特性:

• VIN Range: 2.7V to 5.5V

• Up to 93% Max Power Efficiency

• 1% Current Matching Accuracy Between Channels

• Three simple PWM dimming for RGB or WLED

• Low transition threshold voltage typical 150 mV

• Dual-Mode 1x and 2x Charge Pump

• Drives up to 3 + 3 + 3 Channels of LEDs

• 1.2 MHz Constant Switching Frequency

• VOUT short circuit and Thermal Protections

• Soft Start for reducing inrush current

• Under Voltage Lockout Protection

• IQ <1μA in Shutdown

• Thermally-Enhanced QFN3030-20 Package: Available in “Green” Molding Compound (No Br, Sb)

• Lead Free Finish/ RoHS Compliant

AL3158应用:

• Mobile Phone White LED Backlighting and Indicators

• PDA White LED Backlighting

• Battery-operated Phone Main and Sub Screen White LED Backlighting


图1.AL3158功能方框图

图2.AL3158典型应用电路图