LT1580/LT1580-2.5
7A, Very Low
Dropout Regulator
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DESCRIPTION
FEATURES
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The LT ®1580 is a 7A low dropout regulator designed to
power the new generation of microprocessors. The dropout 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.
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
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.
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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
PowerPCTM Series Power Supplies
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.
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TYPICAL APPLICATION
Dropout Voltage —
Minimum Power Voltage
2.5V Microprocessor Supply
5V
0.2A
2.5V/7A
VOUT
VPOWER
+
+
330µF
OS-CON
LT1580-2.5
VCONTROL
+
10µF
TANT
GND
100µF TANT
AVX TPS
×7
SENSE
ADJ
0.1µF
MINIMUM POWER VOLTAGE (V)
3.3V
7A
1.0
INDICATES GUARANTEED TEST POINTS
0°C ≤ TJ ≤ 125°C
DATA SHEET LIMIT
0.5
TJ = 125°C
TJ = 25°C
1580 TA01
0
0
1
3
5
4
2
OUTPUT CURRENT (A)
6
7
1580 G03
1
