Description

The MAX8630ZETD18 is a charge pump for driving up to 5 white LEDs with a regulated constant current of up to 125mA total. It achieves high efficiency over the full 1-cell Li+ battery input voltage range by utilizing adaptive 1x/1.5x charge-pump modes and very low-dropout current regulators. The regulatory scheme is optimized to ensure low EMI and low input ripple.

Specifications and 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 (MAX8630Z)
--Independent On/Off/Dimming for Main and Sub
--Linear—Full, 31/32nd, 30/32nd, … 1/32nd
• Direct-PWM Dimming (MAX8630Y)
• 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

Application Scenarios

• Display Backlight (Up to 5 LEDs)
• Main (3 LEDs) + Sub (2 LEDs) Displays
• Cell Phones and Smartphones
• PDAs, Digital Cameras, and Camcorders

Comparison

• Maximum efficiency over the full 1-cell Li+ battery input voltage range
• Output overvoltage protection and thermal-derating function protect LEDs
• Low shutdown current at 0.1µA
• Soft-start eliminates inrush current

• Not suitable for driving more than 5 white LEDs
• Only available in a 14-pin, 3mm x 3mm TDFN package