The MAX1553/MAX1554 drive white LEDs in series with a constant current to provide efficient display backlighting in cellular phones, PDAs, and other hand-held devices. The step-up converter includes an internal 40V, low RDSON, N-channel MOSFET switch for high efficiency and maximum battery life. The MAX1553ETA has a current limit of 480mA for driving two to six white LEDs, while the MAX1554 has a current limit of 970mA for driving up to 10 white LEDs. A single analog/PWM Dual Mode input provides two simple means of brightness adjustment. A separate enable input provides on/off control. Soft-start minimizes inrush current during startup. The MAX1553/MAX1554 are available in space-saving 8-pin TDFN 3mm x 3mm packages.
Feature
- Highly Integrated and Flexible Solution for Wide Range of Backlighting Applications
- Constant-Current Regulation for Even LED Illumination
- Internal 40V MOSFET Switch Capable of Driving 10 LEDs
- 2.7V to 5.5V Input Voltage Range
- Analog or PWM Control of LED Intensity
- Optimized for Low Input Ripple
- Soft-Start Minimizes Inrush Current
- High Efficiency Improves Battery Life
- Up to 88% Efficiency Driving 6 LEDs
- Up to 82% Efficiency Driving 9 LEDs (20mA, VCC = 3.6V)
- Tiny 8-Pin, 3mm x 3mm TDFN Package Saves Space
- Small, Low-Profile External Components
Applications
- Cell Phones
- Color Display Backlight
- PDA, Palmtop, and Wireless Handhelds
