FAN5609
LED Driver for Four Parallel-Connected LEDs + Switched Capacitor Boost

Capable of supporting up to four parallel LEDs, the FAN5609 features constant current source matching across all LEDs for precise brightness consistency—with no external parts needed. This driver gives designers the flexibility of using V_F-matched or V_F-unmatched LEDs. The FAN5609 features both digital and PWM brightness controls.

The FAN5609 uses an integrated switched capacitor boost converter and fractional switching techniques to dynamically regulate output voltage. The capacitor boost provides fractional (1.5x) and double (2x) battery voltage. When the battery voltage decays, the boost turns on automatically, enabling the user to still see the display. The FAN5609 is available in both a 14-lead TSSOP and a 16-lead MLP package. For pricing and availability information, visit www.fairchildsemi.com/pf/FA/FAN5609.html. A FAN5609 demo board is also available. Please contact your local sales representative for more information.

Features
- Parallel driver for low and high V_F LEDs
- Integrated switched capacitor boost
- Constant current source for uniform brightness
- Low EMI, low ripple
- No external components needed for current matching
- Integrated DAC for digital and PWM brightness controls
- Up to 20mA driving current for each LED
- 14-lead TSSOP and 16-lead MLP packages

Applications
- Cell phones
- PDA, DSC, MP3 players
- Handheld computers
- LED displays
- Keyboard backlight