Switched-Capacitor Voltage Inverters
Inductorless Power Supply for Pager LCD
DescriptionThe 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.
- 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
- Battery-Powered Applications
- Cell Phones
- Handy-Terminals, PDAs
- Medical Instruments
- Small LCD Panels
Technical DocumentsApp Note 971 Tiny Charge Pump Provides Highly Reliable Low-Cost Solution to Negative Reference Voltage
Tutorial 737 Choosing the Right Power-Supply IC for your Application
Additional ResourcesHow to Design a Negative Voltage Reference Using MAX828
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|
- 8A Switched Capacitor Converter
- 2S to 1S Battery Voltage Conversion (VOUT = VIN/2)
- Integrated Power Switches