General Description
●The LM3508 is a synchronous boost converter (no external Schottky diode required) that provides a constant current output. It is designed to drive up to 4 series white LEDs at 30mA from a single-cell Li-Ion battery. A single low power external resistor is used to set the maximum LED current. The LED current can be adjusted by applying a PWM signal of up to 100kHz to the DIM pin. Internal soft-start circuitry is designed to eliminate high in-rush current at start-up.
●Features
●Drives 4 Series White LEDs with up to 30mA
●>80% Peak Efficiency
●Up to 100kHz PWM Brightness Control
●Accurate ±5% LED Current Regulation across VIN range
●Internal Synchronous PFET (No Schottky Diode Required)
●True Shutdown Isolation
●Output Short-Circuit Protection
●17.5V Over-Voltage Protection
●Internal Soft-Start Eliminates Inrush Current
●Wide Input Voltage Range: 2.7V to 5.5V
●850kHz Fixed Frequency Operation
●Low Profile 9-Bump Micro-SMD Package (1.514mm x 1.514mm x 0.6mm)