SOT23, Switched-Capacitor Voltage Inverters with Shutdown

The ultra-small MAX1719/MAX1720/MAX1721 monolithic, CMOS charge-pump inverters accept input voltages ranging from +1.5V to +5.5V. The MAX1720 operates at 12kHz, and the MAX1719/MAX1721 operate at 125kHz. High efficiency, small external components, and logic-controlled shutdown make these devices ideal for both battery-powered and board-level voltage conversion applications.

Oscillator control circuitry and four power MOSFET switches are included on-chip. A typical MAX1719/MAX1720/MAX1721 application is generating a -5V supply from a +5V logic supply to power analog circuitry. All three parts come in a 6-pin SOT23 package and can deliver a continuous 25mA output current.

For pin-compatible SOT23 switched-capacitor voltage inverters without shutdown (5-pin SOT23), see the MAX828/MAX829 and MAX870/MAX871 data sheets. For applications requiring more power, the MAX860/MAX861 deliver up to 50mA. For regulated outputs (up to -2 x VIN), refer to the MAX868. The MAX860/MAX861 and MAX868 are available in space-saving µMAX® packages.

Applications

* Battery-Powered Applications * GaAs PA Bias Supply * Handy-Terminals, PDAs * Local Negative Supply from a Positive Supply * Small LCD Panels

* 1nA Logic-Controlled Shutdown

* 6-Pin SOT23 Package

* 99.9% Voltage Conversion Efficiency

* 50µA Quiescent Current (MAX1720)

* +1.5V to +5.5V Input Voltage Range

* 25mA Output Current

* Requires Only Two 1µF Capacitors (MAX1719/MAX1721)