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 (60A for the MAX828) make these devices ideal for both battery-powered and boardlevel 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.