Switched-Capacitor Voltage Inverters

The ultra-small MAX828/MAX829 monolithic, CMOS charge-pump inverters accept input voltages ranging from +1.5V to +5.5V. The MAX828 operates at 12kHz, and the MAX829 operates at 35kHz. Their high efficiency (greater than 90% over most of the load-current range) and low operating current (60µA for the MAX828) make these devices ideal for both battery-powered and board-level voltage-conversion applications.

The MAX828/MAX829 combine low quiescent current and high efficiency. Oscillator control circuitry and four power MOSFET switches are included on-chip. Applications include generating a -5V supply from a +5V logic supply to power analog circuitry. Both parts come in a 5-pin SOT23-5 package and can deliver 25mA with a voltage drop of 500mV.

For a similar device with logic-controlled shutdown, refer to the MAX1719/MAX1720/MAX1721. For applications requiring more power, the MAX860 delivers up to 50mA with a voltage drop of 600mV, in a space-saving µMAX® package.

Applications

* Battery-Powered Applications * Cell Phones * Handy-Terminals, PDAs * Medical Instruments * Small LCD Panels

* 5-Pin SOT23-5 Package

* 95% Voltage Conversion Efficiency

* Inverts Input Supply Voltage

* 60µA Quiescent Current (MAX828)

* +1.5V to +5.5V Input Voltage Range

* Requires Only Two Capacitors

* 25mA Output Current