LT1117/LT1117-2.85
LT1117-3.3/LT1117-5
800mA Low Dropout
Positive Regulators
Adjustable and Fixed 2.85V,
3.3V, 5V
DESCRIPTIO
The LT
®
1117 is a positive low dropout regulator designed
to provide up to 800mA of output current. The device is
available in an adjustable version and fixed output voltages
of 2.85V, 3.3V and 5V. The 2.85V version is designed
specifically to be used in Active Terminators for the SCSI
bus. All internal circuitry is designed to operate down to 1V
input to output differential. Dropout voltage is guaranteed
at a maximum of 1.2V at 800mA, decreasing at lower load
currents. On chip trimming adjusts the reference/output
voltage to within
±
1%. Current limit is also trimmed in
order to minimize the stress on both the regulator and the
power source circuitry under overload conditions.
The low profile surface mount SOT-223 package allows
the device to be used in applications where space is
limited. The LT1117 requires a minimum of 10µF of output
capacitance for stability. Output capacitors of this size or
larger are normally included in most regulator designs.
Unlike PNP type regulators where up to 10% of the output
current is wasted as quiescent current, the quiescent
current of the LT1117 flows into the load, increasing
efficiency.
, LTC and LT are registered trademarks of Linear Technology Corporation.
FEATURES
s
s
s
s
s
s
s
Space Saving SOT-223 Surface Mount Package
3-Terminal Adjustable or Fixed 2.85V, 3.3V, 5V
Output Current of 800mA
Operates Down to 1V Dropout
Guaranteed Dropout Voltage at Multiple Current Levels
0.2% Line Regulation Max
0.4% Load Regulation Max
APPLICATIO S
s
s
s
s
s
Active SCSI Terminators
High Efficiency Linear Regulators
Post Regulators for Switching Supplies
Battery Chargers
5V to 3.3V Linear Regulators
TYPICAL APPLICATIO
Dropout Voltage (V
IN
– V
OUT
)
1.4
1.2
DROPOUT VOLTAGE (V)
Active Terminator for SCSI-2 Bus
110Ω
110Ω
LT1117-2.85
IN
4.75V TO
5.25V
OUT
GND
10µF
110Ω
18 TO 27
LINES
1.0
T
J
= 25°C
0.8
0.6
0.4
0.2
T
J
= 125°C
+
+
22µF
110Ω
INDICATES GUARANTEED TEST POINT
LT1117 • TA01
0
0
100 200 300 400 500 600 700 800
OUTPUT CURRENT (mA)
LT1117 • TPC01
U
U
U
–40°C
≤
T
J
< 0°C
0°C
≤
T
J
≤
125°C
1
LINER [ LINEAR TECHNOLOGY ]
