The TPS6040x family of devices generates an unregulated negative output voltage from an input voltage ranging from 1.6 V to 5.5 V. The devices are typically supplied by a preregulated supply rail of 5 V or 3.3 V. Due to its wide input voltage range, two or three NiCd, NiMH, or alkaline battery cells, as well as one Li-Ion cell can also power them.
Only three external 1-µF capacitors are required to build a complete DC-DC charge pump inverter. Assembled in a 5-pin SOT-23 package, the complete converter can be built on a 50-mm2 board area. Additional board area and component count reduction is achieved by replacing the Schottky diode that is typically needed for start-up into load by integrated circuitry.
Features
• Inverts Input Supply Voltage
• Up to 60-mA Output Current
• Only Three Small 1-µF Ceramic Capacitors Needed
• Input Voltage Range From 1.6 V to 5.5 V
• PowerSave-Mode for Improved Efficiency at Low Output Currents (TPS60400)
• Device Quiescent Current Typical 65 µA
• Integrated Active Schottky-Diode for Start-up Into Load