LM1085 Datasheet, PDF (1/2 Pages) National Semiconductor (TI) – 3A Low Dropout Positive Regulators

3A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)
LM1085
FEATURES
● Low Dropout Voltage 500mV at 3A Output Current
● Fast Transient Response
● 0.015% Line Regulation
● 0.1% Load Regulation
● Internal Thermal and Current Limiting
● Adjustable or Fixed Output Voltage(1.5, 2.5, 2.85, 3.0, 3.3, 5.0V)
● Surface Mount Package SOT-223 & TO-263 (D2 Package)
● 100% Thermal Limit Burn-in
TO-220 PKG
APPLICATIONS
TO-263 PKG
● Battery Charger
● Adjustable Power Supplies
● Constant Current Regulators
● Portable Instrumentation
● High Efficiency Linear Power Supplies
● High Efficiency "Green" Computer Systems
● SMPS Post-Regulator
1. Adj/Gnd 2. Output 3. Input
● Power PC Supplies
● Powering VGA & Sound Card
ORDERING INFORMATION
Device & Marking
Package
LM1085T-X.X
TO-220
LM1085R-X.X
TO263 (D2)
DESCRIPTION
(XX=Vout=1.5V, 2.5V, 2.85V, 3.0V, 3.3V, 5.0V
Adjustable= AD)
The LM1085 is a low dropout three terminal regulator with 3A output current capability.
The output voltage is adjustable with the use of a resistor divider. Dropout is guaranteed at a maximum
of 500 mV at maximum output current.
It's low dropout voltage and fast transient response make it ideal for low voltage microprocessor
applications. Internal current and thermal limiting provides protection against any overload condition
that would create excessive junction temperature.
TEST & TYPICAL APPLICATION CIRCUIT
V_IN
5V
+
C1
10㎌
3
2
LM1085
1 ^ADJ
V_REF
RF1
124Ω
1%
RF2
205Ω
1%
V_OUT
3.33V
C2
10㎌
V_REF=V_OUT-V_ADJ=1.25V(Typ.)
V_OUT=V_REFx(1+RF2/RF1)+I_ADJxRF2
I_ADJ=55㎂(Typ.)
(1) C1 Needed if device is far away
from filter capacitors.
(2) C2 Required for stability
Adjustable Voltage Regulator
Mar. 2006 - Rev 06
84
HTC