500mA Output Current Low Noise Dual Mode Step-Up Charge Pumps

The LTC3203/LTC3203-1/LTC3203B/LTC3203B-1 are low noise, high efficiency charge pump DC/DC converters capable of driving loads up to 500mA from a 2.7V to 5.5V input. Low external parts count (two flying capacitors and bypass capacitors at VIN and VOUT) make the LTC3203 family ideally suited for small, battery-powered applications.

Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small external capacitors. The LTC3203/LTC3203-1 feature Burst Mode operation at light load to achieve high efficiency whereas the LTC3203B/LTC3203B-1 operate at constant frequency to achieve lowest noise operation.

The LTC3203-1/LTC3203B-1 have a user selectable fixed output voltage of 4.5V or 5V to power LEDs or logic circuits. The FB pin of the LTC3203/LTC3203B can be used to program the desired output voltage. The parts are short-circuit and over temperature protected and are available in a low profile (3mm × 3mm) DFN package.

Applications

* High Current LED Backlight Supply for Cellphones/PDAs

* Cellphone Camera Light Supply

* General Purpose 3.3V or Li-Ion to 5V Supply

* USB ON THE GO(OTG) Devices

* Selectable Dual Mode Operation: 1:1.5 or 1:2

* High Output Current: Up to 500mA

* Low Noise Constant Frequency (1MHz/0.9MHz) Operation

* VIN Range: 2.7V to 5.5V

* Adjustable Output Voltage (LTC3203/LTC3203B)

* User Selectable Fixed Output Voltages: 4.5V or 5V (LTC3203-1 and LTC3203B-1)

* Automatic Burst Mode® Operation with IQ ~ 120µA (LTC3203/LTC3203-1)

* Constant Freqency Operation at All Loads (LTC3203B/LTC3203B-1)

* Soft-Start Limits Inrush Current at Turn-On

* Short-Circuit/Thermal Protection

* Shutdown Disconnects Load from Input

* Shutdown Current: < 1µA

* Available in a 10-pin (3mm × 3mm) DFN Package