19-2526; Rev 0; 7/02
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White LED Current
Regulator with 1x/1.
5x High-Efficiency Charge Pump
General Description
The MAX1570 fractional charge pump drives up to five white LEDs with regulated constant current for uniform intensity.
The MAX1570 maintains the highest possible efficiency over the full 1-cell lithium-ion (Li+) battery input voltage range by utilizing a 1x/1.
5x fractional charge pump and very-low-dropout current
regulators.
The MAX1570 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 the full-scale LED current, while two digit...