LTC1261L
Switched Capacitor
Regulated Voltage Inverter
FEATURES DESCRIPTION
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Regulated Negative Voltage from a The LTC 1261L is a switched-capacitor voltage inverter
Single Positive Supply designed to provide a regulated negative voltage from a
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REG Pin Indicates Output is in Regulation single positive supply. The LTC1261L operates from a
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Adjustable or Fixed Output Voltages single 2.7V to 5.25V supply and provides an adjustable
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Output Regulation: 4.5% output voltage from 1.23V to 5V. The LTC1261L-4/
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Supply Current: 650A Typ LTC1261L-4.5 needs a single 4.5V to 5.25V supply and
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Shutdown Mode Drops Supply Current to 5A provides a fixed output voltage of 4V to 4.5V respec-
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Up to 20mA Output Current tively. Three external capacitors are required: a 0.1F flying
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Requires Only Three or Four External Capacitors capacitor and an input and output bypass capacitors. An
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Available in MS8 and SO-8 Packages optional compensation capacitor at ADJ (COMP) can be
used to reduce the output voltage ripple.
Each version of the LTC1261L will supply up to 20mA
APPLICATIONS
output current with guaranteed output regulation of 4.5%.
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GaAs FET Bias Generators
The LTC1261L includes an open-drain REG output that
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Negative Supply Generators
pulls low when the output is within 5% of the set value.
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Battery-Powered Systems
Quiescent current is typically 650A when operating and
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Single Supply Applications
5A in shutdown.
The LTC1261L is available in 8-pin MSOP and SO packages.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
Waveforms for 4V Generator with Power Valid
4V Generator with Power Valid
0V
5V
OUT
1 8
5V
V SHDN
CC
10k
4V
2
7
+
C1 REG POWER VALID
C1 C2
5V
LTC1261L-4
1F 0.1F
3 6
V = 4V SHDN
OUT
C1 OUT
AT 10mA 0V
C4
4 5
3.3F
+
GND COMP
5V
C3*
POWER VALID
100pF
0V
1261L TA01
*OPTIONAL
1261L TA02
0.1ms/DIV
1261lfa
1LTC1261L
ABSOLUTE MAXIMUM RATINGS (Note 1)
Supply Voltage (Note 2) ...........................................5.5V Output Short-Circuit Duration ......................... Indefinite
Output Voltage (Note 3) ............................0.3V to 5.3V Commercial Temperature Range (Note 4) .... 0C to 70C
Total Voltage, V to V (Note 2) ........................10.8V Industrial Temperature Range (Note 4) ... 40C to 85C
CC OUT
SHDN Pin ......................................0.3V to (V + 0.3V) Storage Temperature Range ................... 65C to 150C
CC
REG Pin........................................................ 0.3V to 6V Lead Temperature (Soldering, 10 sec) .................. 300C
ADJ Pin .............................(V 0.3V) to (V + 0.3V)
OUT CC
PIN CONFIGURATION
TOP VIEW
TOP VIEW
V 1 8 SHDN
CC
V 1 8 SHDN
CC
+
+
C1 2 7 REG
C1 2 7 REG
C1 3 6 OUT
C1 3 6 OUT
GND 4 5 ADJ (COMP)
GND ADJ (COMP)
4 5
MS8 PACKAGE
8-LEAD PLASTIC MSOP
S8 PACKAGE
T = 150C, = 200C/W
JMAX JA 8-LEAD PLASTIC SO
T = 150C, = 135C/W
JMAX JA
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC1261LCMS8#PBF LTC1261LCMS8#TRPBF LTFM 8-Lead Plastic MSOP 0C to 70C
LTC1261LIMS8#PBF LTC1261LIMS8#TRPBF LTFM 8-Lead Plastic MSOP 40C to 85C
LTC1261LCMS8-4#PBF LTC1261LCMS8-4#TRPBF LTFN 8-Lead Plastic MSOP 0C to 70C
LTC1261LIMS8-4#PBF LTC1261LIMS8-4#TRPBF LTFN 8-Lead Plastic MSOP 40C to 85C
LTC1261LCMS8-4.5#PBF LTC1261LCMS8-4.5#TRPBF LTFP 8-Lead Plastic MSOP 0C to 70C
LTC1261LIMS8-4.5#PBF LTC1261LIMS8-4.5#TRPBF LTFP 8-Lead Plastic MSOP 40C to 85C
LTC1261LCS8#PBF LTC1261LCS8#TRPBF 1261L 8-Lead Plastic SO 0C to 70C
LTC1261LIS8#PBF LTC1261LIS8#TRPBF 1261L 8-Lead Plastic SO 40C to 85C
LTC1261LCS8-4#PBF LTC1261LCS8-4#TRPBF 1261L4 8-Lead Plastic SO 0C to 70C
LTC1261LIS8-4#PBF LTC1261LIS8-4#TRPBF 1261L4 8-Lead Plastic SO 40C to 85C
LTC1261LCS8-4.5#PBF LTC1261LCS8-4.5#TRPBF 261L45 8-Lead Plastic SO 0C to 70C
LTC1261LIS8-4.5#PBF LTC1261LIS8-4.5#TRPBF 261L45 8-Lead Plastic SO 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: