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LM2731
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SNVS217F –MAY 2004–REVISED NOVEMBER 2012
LM2731 0.6/1.6 MHz Boost Converters With 22V Internal FET Switch in SOT-23
Check for Samples: LM2731
1
FEATURES
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).
2
•
22V DMOS FET Switch
•
1.6 MHz (“X”), 0.6 MHz (“Y”) Switching
Frequency
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 solutions perfect for boosting to
voltages up to 20V.
•
•
•
•
•
•
•
•
Low RDS(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
These parts have a logic-level shutdown pin that can
be used to reduce quiescent current and extend
battery life.
Uses Tiny Capacitors and Inductors
Cycle-by-Cycle Current Limiting
Internally Compensated
Protection is provided through cycle-by-cycle current
limiting and thermal shutdown. Internal compensation
simplifies design and reduces component count.
APPLICATIONS
•
•
•
•
•
White LED Current Source
PDA’s and Palm-Top Computers
Digital Cameras
Table 1. Switch Frequency
X
Y
1.6 MHz
0.6 MHz
Portable Phones and Games
Local Boost Regulator
Typical Application Circuit
Efficiency vs Load Current
D1
L1/10mH
100
90
MBR0520
5 VIN
5 - 12V Boost
^ó_ ëꢀŒ•]}v
U1
VIN
SW
12V
OUT
500mA
(TYP)
R3
51K
R1/117K
LM2731 —X“
FB
SHDN
SHDN
GND
80
70
C1
2.2mF
CF
R2
13.3K
C2
220pF
GND
4.7mF
0
500
100 200 300 400
LOAD CURRENT (mA)
Efficiency vs Load Current
D1
MBR0520
L1/6.8mH
100
90
3.3 VIN
SHDN
3.3 -5V Boost
^ò_ ëꢀŒ•]}v
U1
VIN
SW
5V
OUT
R3
51K
R1/40.5K
LM2731 —Y“
FB
700mA
(TYP)
SHDN
GND
80
70
C1
2.2mF
CF
470pF
R2
13.3K
C2
22mF
GND
0
400 600
800
200
LOAD CURRENT (mA)
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2004–2012, Texas Instruments Incorporated