LT1580/LT1580-2.5
7A, Very Low
Dropout Regulator
FEATURES
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DESCRIPTION
The LT ®1580 is a 7A low dropout regulator designed to
power the new generation of microprocessors. The drop-
out voltage of this device is 100mV at light loads rising to
just 540mV at 7A. To achieve this dropout, a second low
current input voltage 1V greater than the output voltage, is
required. The device can also be used as a single supply
device where dropout is comparable to an LT1584.
Several other new features have been added to the LT1580.
A remote SENSE pin is brought out. This feature virtually
eliminates output voltage variations due to load changes.
Typical load regulation, measured at the SENSE pin, for a
load current step of 100mA to 7A is less than 1mV.
The LT1580 has fast transient response, equal to the
LT1584. On fixed voltage devices, the ADJ pin is brought
out. A small capacitor on the ADJ pin further improves
transient response.
This device is ideal for generating processor supplies of
2V to 3V on motherboards where both 5V and 3.3V
supplies are available.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a registered trademark of Intel Corporation.
PowerPC is a trademark of IBM Corporation.
Low Dropout, 540mV at 7A Output Current
Fast Transient Response
Remote Sense
1mV Load Regulation
Fixed 2.5V Output and Adjustable Output
No Supply Sequencing Problems in
Dual Supply Mode
APPLICATIONS
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Microprocessor Supplies
Post Regulators for Switching Supplies
High Current Regulators
5V to 3.XXV for Pentium
®
Processors Operating
at 90MHz to 166MHz and Beyond
3.3V to 2.9V for Portable Pentium Processor
PowerPC
TM
Series Power Supplies
TYPICAL APPLICATION
Dropout Voltage —
Minimum Power Voltage
2.5V Microprocessor Supply
3.3V
7A
V
POWER
V
OUT
1.0
INDICATES GUARANTEED TEST POINTS
0°C
≤
T
J
≤
125°C
+
330µF
OS-CON
+
LT1580-2.5
100µF TANT
AVX TPS
×
7
MINIMUM POWER VOLTAGE (V)
2.5V/7A
0.5
T
J
= 125°C
T
J
= 25°C
5V
0.2A
V
CONTROL
SENSE
ADJ
0.1µF
1580 TA01
+
10µF
TANT
GND
0
0
1
3
5
4
2
OUTPUT CURRENT (A)
6
7
1580 G03
U
U
U
DATA SHEET LIMIT
1
LINER [ LINEAR TECHNOLOGY ]
