LM3350 Datasheet, PDF (1/8 Pages) National Semiconductor (TI) – Switched Capacitor Voltage Converter

December 1999
LM3350
Switched Capacitor Voltage Converter
General Description
The LM3350 is a CMOS charge-pump voltage converter
which efficiently provides a 3.3V to 5V step-up, or 5V to 3.3V
step-down. The LM3350 uses four small, low cost capacitors
to provide the voltage conversion. It eliminates the cost, size
and radiated EMI related to inductor based circuits, or the
power loss of a linear regulator. Operating power conversion
efficiency greater than 90% provides ideal performance for
battery powered portable systems.
The architecture provides a fixed voltage conversion ratio of
3/2 or 2/3. Thus it can be used for other DC-DC conversions
as well.
Key Specifications
n 800 kHz switch frequency allows use of very small,
inexpensive capacitors.
n 4.2Ω typical step-up output impedance
n 1.8Ω typical step-down output impedance
n 90% typical power conversion efficiency at 50 mA
n 250 nA typical shutdown current
Features
n Conversion of 3.3V to 5V, or 5V to 3.3V
n Small Mini SO-8 package
n No inductor required
Applications
n Any mixed 5V and 3.3V system
n Laptop computers and PDAs
n Handheld instrumentation
n PCMCIA cards
Ordering Information
Order Number
Package Type
LM3350MMX
LM3350MM
Mini SO-8
Mini SO-8
Basic Operating Circuits
NSC Package
Drawing
MUA08A
MUA08A
Step-Up Converter
Package
Marking
S00A
S00A
Supplied As
3500k Units on Tape and Reel
1000 Units on Tape and Reel
Step-Down Converter
Connection Diagram
DS100002-1
Mini SO8 Package
DS100002-3
Top View
© 1999 National Semiconductor Corporation DS100002
DS100002-2
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