White LED
Charge Pump With LDO
FEATURES
- Powers Up to 6 LEDs for
BackLight & One 5V LDO Supply.
- Up to 25mA/LED Drive
for Backlight
- Up to 100mA Total Drive
for LDO
- Single-Wire 8-Step
Brightness/Voltage Control
- Over temperature Over
Voltage, Output Short Protection
- Soft Start with Low
Input Ripple and EMI
- Maximized Efficiency
- 2.7V to 5.5V Supply
Voltage Range
- 3mmx3mm 16-Pin QFN
Package
DESCRIPTION
The BL260 is a low noise charge pump LED driver with regulated
constant current sink for uniform intensity. It is designed to drive six LEDs (LED1-LED6) at up to 25mA per
LED for backlighting application and one
fixed 5 volt supply (V5) for general purpose application which can supply up
to 100mA of DC power. The BL260 requires
only four small ceramic capacitors and one current set resistor for a complete
LED power supply or add one additional capacitor for LDO application.
Built-in soft-start circuitry prevents excessive
inrush current during start-ups. The 1MHz fixed-frequency switching allows for
tiny external components, and the regulation scheme is optimized to ensure low
EMI and low input ripple. Backlight
full-scale current settings is set by an external resistor on RB pin.
Shutdown mode and LED current output levels is
selected via logic input ENB pin. ENB is toggled to adjust the LED currents via
internal counters and DACs. The part is shut down when ENB is Low for >10µs.
The charge pump optimizes efficiency based on the
voltage across the LED current sources. The BL260 is available in a 3mm × 3mm
16-lead QFN package.
