Single Cell to 3.3V Regulated Charge Pump DC/DC Converter

The LTC1502-3.3 is a quadrupler charge pump DC/DC converter that produces a regulated 3.3V output from a single alkaline cell input. It requires only five small external capacitors—no inductors are required. Low supply current (40µA typical, 5µA in shutdown) and minimal external components make the LTC1502-3.3 ideal for space and power conscious single-cell applications. The total printed circuit board area of the circuit shown below is less than 0.125in2.

Forcing the C1−/SHDN pin through an external resistive pull-down puts the part into shutdown mode. During shutdown, the internal oscillator is stopped and the load is disconnected from VIN. An internal pull-up current on the C1−/SHDN pin forces the part back into normal operation once the pull-down resistance is removed.

The LTC1502-3.3 is short-circuit protected and survives an indefinite VOUT short to ground. The LTC1502-3.3 is available in 8-pin MSOP and SO packages.

Applications

* Pagers

* Battery Backup Supplies

* Portable Electronic Equipment

* Handheld Medical Instruments

* Glucose Meters

* Input Voltage Range: 0.9V to 1.8V

* 0.9V Guaranteed Start-Up Voltage

* Regulated Output Voltage: 3.3V ±4%

* Output Current: 10mA (VIN ≥ 1V)

* No Inductors

* Shutdown Disconnects Load from VIN

* Low Operating Current: 40µA

* Low Shutdown Current: 5µA

* Short-Circuit and Overtemperature Protected

* Application Circuit Fits in <0.125in2 PCB Area

* Available in 8-Pin MSOP and SO Packages