LT1965
1.1A, Low Noise,
Low Dropout Linear Regulator
FEATURES
DESCRIPTION
The LT®1965 is a low noise, low dropout linear regulator.
The device supplies 1.1A of output current with a 290mV
typical dropout voltage. Operating quiescent current is
500μA, reducing to <1μA in shutdown. Quiescent current
is well controlled; it does not rise in dropout as with many
other regulators. The LT1965 regulator has very low out-
put noise which makes it ideal for sensitive RF and DSP
supply applications.
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Output Current: 1.1A
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Dropout Voltage: 290mV
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Low Noise: 40μV
500μA Quiescent Current
(10Hz to 100kHz)
RMS
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Wide Input Voltage Range: 1.8V to 20V
No Protection Diodes Needed
Controlled Quiescent Current in Dropout
Adjustable Output from 1.20V to 19.5V
< 1μA Quiescent Current in Shutdown
Stable with 10μF Output Capacitor
Stable with Ceramic, Tantalum or Aluminum
Electrolytic Capacitors
Reverse Battery Protection
No Reverse Current
Current Limit with Foldback Protection
Thermal Limiting
5-Lead TO-220, DD-PAK, Thermally Enhanced 8-Lead
Output voltage ranges from 1.20V to 19.5V. The LT1965
regulator is stable with output capacitors as low as 10μF.
Internal protection circuitry includes reverse battery pro-
tection, current limiting with foldback, thermal limiting
and reverse current protection. The LT1965 is available
as an adjustable device with a 1.20V reference voltage.
The package offering includes the 5-lead TO-220, 5-lead
DD-PAK as well as the thermally enhanced 8-lead MSOP
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and 8-lead 3mm × 3mm DFN.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
MSOP and 8-Lead 3mm × 3mm DFN Packages
APPLICATIONS
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Logic Power Supplies
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Post Regulator for Switching Supplies
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Low Noise Instrumentation
TYPICAL APPLICATION
Dropout Voltage
3.3V to 2.5V Regulator
400
T
= 25°C
J
350
300
250
200
150
100
50
2.5V
1.1A
IN
OUT
ADJ
+
> 3V
+
V
IN
5.11k
1%
10μF*
10μF*
TO 20V
LT1965
SHDN
GND
4.75k
1%
*CERAMIC, TANTALUM OR
ALUMINUM ELECTROLYTIC
1965 TA01
0
0
0.2
0.6
0.8
1
1.2
0.4
OUTPUT CURRENT (A)
1965 TA01b
1965f
1