1

LT1587-1.5

Fixed 1.5V, 3A

Low Dropout

Fast Response

GTL+ Regulator

The LT

with a fixed 1.5V output voltage and 3A output current

capability. The design is optimized for low voltage applica-

tions where transient response and minimum input voltage

are critical. Similar to the LT1085, it has lower dropout and

faster transient response. These improvements make it

ideal for low voltage microprocessor applications, espe-

cially as the regulator in an Intel Pentium Pro processor

GTL+ supply.

Current limit is trimmed to ensure specified output current

and controlled short-circuit current. On-chip thermal lim-

iting provides protection against any combination of over-

load that creates excessive junction temperatures.

The LT1587-1.5 is available in both the through-hole and

surface mount versions of the industry standard 3-pin

TO-220 power package.

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Fast Transient Response

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Guaranteed Dropout Voltage at Multiple Currents

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Load Regulation: 0.05% Typ

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Trimmed Current Limit

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On-Chip Thermal Limiting

FEATURES

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Intel Pentium

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Low Voltage Logic Supplies

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Battery-Powered Circuitry

, LTC and LT are registered trademarks of Linear Technology Corporation.

Pentium is a registered trademark of Intel Corporation

Intel Pentium Pro Processor GTL+ Supply

C2, C3

100

µF

10V

AVX TPS

C1

100

µF

10V

AVX TPS

+

C4 TO

C6

1

µF

C8, C9

100

µF

10V

AVX TPS

C10 TO C12

1

µF

C7

100

µF

10V

AVX TPS

R1

75

Ω

R5

100

Ω

R2

150

Ω

R4

150

Ω

R7

100

Ω

R8

100

Ω

R6

100

Ω

R3

75

Ω

Q1

Q3

+

+

GND

LT1587-1.5

3.3V

3.3V

3A

3A

GND

LT1587-1.5

142 TOTAL SIGNAL LINES

•

•

•

C13

0.1

µF

C14

0.1

µF

Q4

Q2

+

LT1587 • TA01

RX

TX

RX

TX

RX

TX

RX

TX

NOTE: LTC RECOMMENDS SEPARATE

TO ENSURE CURRENT SHARING

BETWEEN THE REGULATORS AND TO