The MAX1570ETE+ is a white LED current regulator with 1x/1.5x high efficiency charge pump in 16 pin TQFN package. This fractional charge pump drives up to five white LEDs with regulated constant current for uniform intensity. The MAX1570 maintains highest possible efficiency over full 1-cell lithium-ion (Li+) battery input voltage range by utilizing 1x/1.5x fractional charge pump and very low dropout current regulators. It operates with 1MHz fixed frequency switching allowing for tiny external components. The regulation scheme is optimized to ensure low EMI and low input ripple. An external resistor sets full scale LED current while two digital inputs control on/off and select between three levels of brightness. A pulse width modulation (PWM) signal can also be used to modulate LED brightness.
Operating supply voltage range from 2.7V to 5.5V
Operating temperature range from -40°C to 85°C
Excellent 0.3% LED to LED current matching
30mA/LED drive capability
Switching frequency of 1MHz at TA = 0°C to 85°C
Eliminates ballast resistors
Digital or PWM LED dimming control
2mA supply current (1MHz switching, no load) and 0.1μA shutdown supply current at TA = 0°C to 85°C
Soft start limits inrush current and thermal shutdown protection
No external inductor, schottky or zener diode required
(EN)
