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 LowOutput Currents (TPS60400)
• Device Quiescent Current Typical 65 µA
• Integrated Active Schottky-Diode for Start-up Into
Load
• Small 5-Pin SOT-23 Package
• Evaluation Module Available TPS60400EVM-178

Applications
• LCD Bias
• GaAs Bias for RF Power Amps
• Sensor Supply in Portable Instruments
• Bipolar Amplifier Supply
• Medical Instruments
• Battery-Operated Equipment

Description
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.
The TPS6040x can deliver a maximum output current
of 60 mA with a typical conversion efficiency of
greater than 90% over a wide output current range.
Three device options with 20-kHz, 50-kHz, and 250-
kHz fixed-frequency operation are available.
TPS60400 comes with a variable switching frequency
to reduce operating current in applications with a wide
load range and enables the design with low-value
capacitors.