LT1964
200mA, Low Noise,
Low Dropout Negative
Micropower Regulator
FEATURES
DESCRIPTION
TheLT®1964isamicropowerlownoise,lowdropoutnega-
tive regulator. The device is capable of supplying 200mA
of output current with a dropout voltage of 340mV. Low
quiescent current (30μA operating and 3μA shutdown)
makes the LT1964 an excellent choice for battery-pow-
ered applications. Quiescent current is well controlled in
dropout.
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Low Noise: 30μV
(10Hz to 100kHz)
RMS
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Low Quiescent Current: 30μA
Low Dropout Voltage: 340mV
Output Current: 200mA
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Fixed Output Voltage: –5V
Adjustable Output from –1.22V to –20V
Positive or Negative Shutdown Logic
3μA Quiescent Current in Shutdown
Stable with 1μF Output Capacitor
Stable with Aluminum, Tantalum, or Ceramic
Capacitors
Thermal Limiting
Low Profile (1mm) ThinSOT™ and (0.75mm) 8-Pin
3mm × 3mm DFN Packages
Other features of the LT1964 include low output noise.
With the addition of an external 0.01μF bypass capacitor,
outputnoiseisreducedto30μV
overa10Hzto100kHz
RMS
bandwidth. The LT1964 is capable of operating with small
capacitors and is stable with output capacitors as low
as 1μF. Small ceramic capacitors can be used without
the necessary addition of ESR as is common with other
regulators. Internal protection circuitry includes reverse
output protection, current limiting, and thermal limiting.
The device is available with a fixed output voltage of –5V
and as an adjustable device with a –1.22V reference volt-
age. The LT1964 regulators are available in a low profile
(1mm) ThinSOT and the low profile (0.75mm) 8-pin
(3mm × 3mm) DFN packages.
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APPLICATIONS
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Battery-Powered Instruments
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Low Noise Regulator for Noise-Sensitive
Instrumentation
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Negative Complement to LT1761 Family of
Positive LDOs
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ThinSOT is
a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
TYPICAL APPLICATION
10Hz to 100kHz Output Noise
–5V Low Noise Regulator
1μF
10μF
GND
V
OUT
30μV
RMS
SHDN
BYP
OUT
V
100μV/DIV
IN
–5.4V
0.01μF
LT1964-5
TO –20V
IN
–5V AT 200mA
30μV
NOISE
RMS
1964 TA01a
1964 TA01b
1ms/DIV
1964fb
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