AL3157:LED Drivers for Displays / Backlights

Part NumberData SheetSPICE ModelFunctionMinimumInput Voltage (V)MaximumInput Voltage (V)Maximum Output Voltage (V)Number of Regulated Output ChannelsMaximum Output Current per Channel (mA)Typical Over-Current Protection Current (mA)Switching Frequency (MHz)Efficiency (%)Quiescent Current (mA)Standby Quiescent Current (µA)SW RDS(ON) (Ω)DimmingOVPSoft StartVFB (V)OperatingTemperatureRange (°C)
AL3157AL3157.pdf-Charge Pump LED Driver2.75.55.5430mA/CH for BUL-1.293210.5PWMYesYes--40 to +85
Description

The AL3157 is a low noise, constant frequency charge pump DC/DC converter that uses a Dual mode load switch (1x), and doubling (2x) conversion for driving white °Cs. Low external part count (one 1µF flying capacitor and two 2.2µF capacitors at VIN and VOUT) make this part ideally suited for small, battery-powered applications The AL3157 drives 3 channels at up to 30mA for small screen backlighting and an additional channel up to 210mA for °C Flash or °C Flashlight – All from a 2.7V to 5.5V input. The AL3157 uses two control inputs (EN1/2) to enable/disable it and PWM dim the °C current. EN2 controls/PWM dims the backlight °Cs at 30mA per channel and EN1 controls/PWM dims the Flash/Flashlight °Cs at 210mA. Each output of the AL3157 is equipped with built-in protection for VOUT short circuit and auto-disable for °C failure conditions. Built-in soft-start circuitry prevents excessive in-rush current during start-up and mode switching. A low-current shutdown feature disconnects the load from VIN to reduce quiescent current less than 1µA. The AL3157 is available in a lead-free, space-saving, thermally enhanced 12-pin 3 x 3mm DFN package.

Application
  • Mobile phone Backlighting + flashlight
  • Mobile phone Backlighting + camera flash
  • Small screen backlighting + auxilliary lighting
Ordering Information
  • AL3157F-7
U-DFN3030-12
AL3157.pdf AL3157
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