LT1175 Datasheet, PDF (1/12 Pages) Linear Technology – 500mA Negative Low Dropout Micropower Regulator

FEATURES
s _{Stable with Wide Range of Output Capacitors}
s _{Operating Current: 45µA}
s _{Shutdown Current: 10µA}
s _{Adjustable Current Limit}
s _{Positive or Negative Shutdown Logic}
s _{Low Voltage Linear Dropout Characteristics}
s _{Fixed 5V and Adjustable Versions}
s _{Tolerates Reverse Output Voltage}
U
APPLICATIO S
s _{Analog Systems}
s _Modems
s _{Instrumentation}
s _{A/D and D/A Converters}
s _{Interface Drivers}
s _{Battery-Powered Systems}
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Typical LT1175 Connection
+
C_IN*
–V_IN
SHDN GND
+
C_OUT
≥ 0.1µF
INPUT
SENSE
– 5V
UP TO 500mA
I_LIM2 LT1175-5 OUT
I_LIM4
*C_IN IS NEEDED ONLY IF REGULATOR IS MORE THAN 6" FROM
INPUT SUPPLY CAPACITOR. SEE APPLICATIONS INFORMATION
SECTION FOR DETAILS
1175 TA01
LT1175
500mA Negative
Low Dropout Micropower
Regulator
DESCRIPTIO
The LT^®1175 is a negative micropower low dropout regu-
lator. It features 45µA quiescent current, dropping to
10µA in shutdown. A new reference amplifier topology
gives precision DC characteristics along with the ability to
maintain good loop stability with an extremely wide range
of output capacitors. Very low dropout voltage and high
efficiency are obtained with a unique power transistor anti-
saturation design. Adjustable and fixed 5V versions are
available.
Several new features make the LT1175 very user-friendly.
The SHDN pin can interface directly to either positive or
negative logic levels. Current limit is user-selectable at
200mA, 400mA, 600mA and 800mA. The output can be
forced to reverse voltage without damage or latchup.
Unlike some earlier designs, the increase in quiescent
current during a dropout condition is actively limited.
The LT1175 has complete blowout protection with current
limiting, power limiting and thermal shutdown. Special
attention was given to the problem of high temperature
operation with micropower operating currents, preventing
output voltage rise under no-load conditions. The LT1175
is available in 8-pin PDIP and SO packages, 3-lead SOT-
223 as well as 5-pin surface mount DD and through-hole
TO-220 packages. The 8-pin SO package is specially
constructed for low thermal resistance.
Minimum Input-to-Output Voltage
1.0
T_J = 25°C
I_LIM2, I_LIM4 TIED TO V_IN
0.8
0.6
0.4
0.2
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
OUTPUT CURRENT (A)
1175 TA02
1