LM2731 0.6/1.6 MHz Boost Converters With 22V Internal FET Switch in SOT-23
July 2003
LM2731
0.6/1.6 MHz Boost Converters With 22V Internal FET
Switch in SOT-23
General Description
The LM2731 switching regulators are current-mode boost
converters operating at fixed frequencies of 1.6 MHz (“X”
option) and 600 kHz (“Y” option).
The use of SOT-23 package, made possible by the minimal
power loss of the internal 1.8A switch, and use of small
inductors and capacitors result in the industry’s highest
power density. The 22V internal switch makes these solu-
tions perfect for boosting to voltages up to 20V.
These parts have a logic-level shutdown pin that can be
used to reduce quiescent current and extend battery life.
Protection is provided through cycle-by-cycle current limiting
and thermal shutdown. Internal compensation simplifies de-
sign and reduces component count.
Switch Frequency
X
1.6 MHz
Y
0.6 MHz
Features
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22V DMOS FET switch
1.6 MHz (“X”), 0.6 MHz (“Y”) switching frequency
Low R
DS
(ON) DMOS FET
Switch current up to 1.8A
Wide input voltage range (2.7V–14V)
Low shutdown current (
<
1 µA)
5-Lead SOT-23 package
Uses tiny capacitors and inductors
Cycle-by-cycle current limiting
Internally compensated
Applications
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White LED Current Source
PDA’s and Palm-Top Computers
Digital Cameras
Portable Phones and Games
Local Boost Regulator
Typical Application Circuit
20059110
20059130
© 2003 National Semiconductor Corporation
DS200591
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