The MAX828/829 are CMOS "chargepump" voltage converters in ultrasmall SOT23 5 lead packages. They invert and/or double an input voltage which can range from +1.5V to +5.5V. Conversion efficiency is typically >95%. Switching frequency is 12kHz for the MAX828 and 35kHz for the MAX829. External component requirement is only two capacitors (3.3F nominal) for standard voltage inverter applications. With a few additional components a positive doubler can also be built. All other circuitry, including control, oscillator, power MOSFETs are integrated onchip. Supply current is 50 A (MAX828) and 115 A (MAX829). The MAX828 and MAX829 are available in a SOT23 5 lead surface mount package.