LT1584/LT1585/LT1587
7A, 4.6A, 3A Low Dropout
Fast Response
Positive Regulators
Adjustable and Fixed
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DESCRIPTIO
FEATURES
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Fast Transient Response
Guaranteed Dropout Voltage at Multiple Currents
Load Regulation: 0.05% Typical
Trimmed Current Limit
On-Chip Thermal Limiting
Standard 3-Pin Power Package
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APPLICATIO S
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PentiumTM Processor Supplies
PowerPCTM Supplies
Other 2.5V to 3.6V Microprocessor Supplies
Low Voltage Logic Supplies
Battery-Powered Circuitry
Post Regulator for Switching Supply
The LT ®1584/LT1585/LT1587 are low dropout threeterminal regulators with 7A, 4.6A and 3A output current
capability, respectively. Design has been optimized for low
voltage applications where transient response and minimum input voltage are critical. Similar to the LT1083/4/5
family, it has lower dropout voltage and faster transient
response. These improvements make it ideal for low voltage microprocessor applications requiring a regulated
2.5V to 3.6V output with an input supply below 7V.
Current limit is trimmed to ensure specified output current
and controlled short-circuit current. On-chip thermal limiting provides protection against any combination of overload that would create excessive junction temperatures.
LT1585/7CM, LT1584/5/7CT
Adjustable
LT1585/7CM-3.3, LT1584/5/7CT-3.3
3.3V Fixed
LT1585CM-3.38, LT1584/5CT-3.38
3.38V Fixed
LT1585/7CM-3.45, LT1584/5/7CT-3.45
3.45V Fixed
LT1585/7CM-3.6, LT1584/5/7CT-3.6
The LT1585/LT1587 are available in both the through-hole
and surface mount versions of the industry standard 3-pin
TO-220 power package. The LT1584 is available in the
through-hole 3-pin TO-220 power package.
3.6V Fixed
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation.
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TYPICAL APPLICATIO
Dropout Voltage vs Output Current
1.5
3.3V, 7A, 4.6A, 3A Regulator
VIN ≥ 4.75V
+
C1
10µF
* REQUIRED FOR STABILITY
LT1584: C2 = 22µF,
LT1585/LT1587: C2 = 10µF
+
3.3V
7A, 4.6A, 3A
C2*
SOLID
TANTALUM
1585 TA01
NOTE: MICROPROCESSOR APPLICATIONS WITH LOAD TRANSIENTS OF 3.8A REQUIRE
OUTPUT DECOUPLING CAPACITANCE > 1300µF ON FIXED VOLTAGE PARTS TO ACHIEVE
< 50mV OF DEVIATION FROM NOMINAL OUTPUT. CONSULT FACTORY FOR DETAILS
INPUT/OUTPUT DIFFERENTIAL (V)
LT1584-3.3
LT1585-3.3
LT1587-3.3
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0
IFULL LOAD
OUTPUT CURRENT (A)
1585 TA02
158457a
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