LM2788 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – 120mA High Efficiency Step-Down Switched Capacitor Voltage Converter

October 2002
LM2788
120mA High Efficiency Step-Down Switched Capacitor
Voltage Converter
General Description
The LM2788 switched capacitor step-down DC/DC con-
verter efficiently produces a 120mA regulated low-voltage
rail from a 2.6V to 5.5V input. Fixed output voltage options of
1.5V, 1.8V, and 2.0V are available. The LM2788 uses mul-
tiple fractional gain configurations to maximize conversion
efficiency over the entire input voltage and output current
ranges. Also contributing to high overall efficiency is the
extremely low supply current of the LM2788: 32µA operating
unloaded and 0.1µA in shutdown.
The optimal external component requirements of the
LM2788 solution minimize size and cost, making the part
ideal for Li-Ion and other battery powered designs. Two 1µF
flying capacitors and two 10µF bypass capacitors are all that
are required, and no inductors are needed.
The LM2788 also features noise-reducing soft-start circuitry,
short-circuit protection and over-temperature protection.
Features
n Output voltage options:
2.0V ± 5%, 1.8V ± 5%, 1.5V ± 6%
n 120mA output current capability
n Multi-Gain and Gain Hopping for Highest Possible
Efficiency - up to 90% Efficient
n 2.6V to 5.5V input range
n Low operating supply current: 32µA
n Shutdown supply current: 0.1µA
n Thermal and short circuit protection
n Available in an 8-Pin MSOP Package
Applications
n Cellular Phones
n Pagers
n H/PC and P/PC Devices
n Portable Electronic Equipment
n Handheld Instrumentation
Typical Application Circuit
20044401
© 2002 National Semiconductor Corporation DS200444
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