General Description

The MAX8630W/MAX8630X charge pumps drive up to 5 white LEDs with regulated constant current up to 125mA total. By utilizing adaptive 1x/1.5x charge-pump modes and very low-dropout current regulators, they achieve high efficiency over the full 1-cell Li+ battery input voltage range. The 1MHz fixed-frequency switching allows for tiny external components, and the regulation scheme is optimized to ensure low EMI and low input ripple. An integrated derating function protects the LEDs from overheating during high ambient temperatures.

Features

♦ 93 Max/85 Avg. Efficiency (PLED/PBATT) Over Li+ Battery Discharge

♦ 1 LED Current Accuracy

♦ 125mA Total Drive Capability

♦ Adaptive 1x/1.5x Mode Switchover

♦ Single-Wire, Serial-Pulse Dimming (MAX8630X)

   Independent On/Off/Dimming for Main and Sub

   Linear—Full, 31/32nd, 30/32nd, … 1/32nd

♦ Direct-PWM Dimming (MAX8630W)

♦ 15, 18, 20, and 25mA Full-Scale Versions

♦ Low 0.1µA Shutdown Current

♦ Soft-Start Eliminates Inrush Current

♦ Output Overvoltage Protection

♦ Thermal-Derating Function Protects LEDs

♦ 14-Pin, 3mm x 3mm TDFN Package

Applications

   Display Backlight (Up to 5 LEDs)

   Main (3 LEDs) + Sub (2 LEDs) Displays

   Cell Phones and Smartphones

   PDAs, Digital Cameras, and Camcorders