More LED driver product information

The FAN5607 generates regulated output current from a battery with input voltage varying between 2.7V to 5.5V. Switch reconfiguration and fractional switching techniques are utilized to achieve high efficiency over the entire input voltage range. A proprietary internal circuitry continuously monitors each LED current loop and automatically adjusts the generated output DC voltage to the lowest minimum value required by the LED having the highest forward voltage. This adaptive nature of the FAN5607 eliminates the need for LED pre-selection (matching) and ensures operation at high efficiency. When the input voltage is sufficiently high to sustain the programmed current level in the LEDs, the FAN5607 re-configures itself to operate as a linear regulator, and the DC-DC converter is turned off. Only two 0.1µF to 1µF bucket capacitors and two 4.7µF input/output capacitors are needed for proper operation. LED current can be programmed using an external resistor. The resistor sets the maximum LED current and a PWM signal applied to the enable pin can modulate that current level between 0mA (off) and the maximum level.

Soft-start circuitry prevents excessive current draw during power on. The device has built-in short circuit protection.

The device is available in 4x4mm 16-lead MLP package.

• Parallel LED Driver Supports all Forward Voltages
• Adaptive V OUT Adjustment to the Highest Diode Voltage
• Internally Matched LED Current Sources
• Built-in Charge Pump has Three Modes of Operation:
  • 1X, 1.5X, and 2X Mode
• Up to 93% Efficiency
• Low EMI, Low Ripple
• Up to 120mA Output Current (4 x 30mA)
• External Resistor to Set Maximum (100%) LED Current
• Enable Input Can be Duty-Cycle-Modulated to Control LED Current Level Between 0 and 100%
• 2.4V to 5.5V Input Voltage Range
• I_CC < 1µA in Shutdown Mode
• 1MHz Operating Frequency
• Shutdown Isolates Output from Input
• Soft-Start Limits Inrush Current
• Short Circuit Protection
• Minimal External Components Needed
• Available in a 4x4mm 16-lead MLP Package

• Cell Phones
• Handheld Computers
• PDA, DSC, MP3 Players
• Keyboard Backlight
• LED Displays