LT1581_15 Datasheet, PDF (1/12 Pages) Linear Technology – 10A, Very Low Dropout Regulators

LT1581/LT1581-2.5
10A, Very Low
Dropout Regulators
FEATURES
s _{Low Dropout, 430mV at 10A Output Current}
s _{Fast Transient Response}
s _{Remote Sense}
s _{1mV Load Regulation}
s _{Fixed 2.5V Output and Adjustable Output}
s _{No Supply Sequencing Problems in}
Dual Supply Mode
U
APPLICATIONS
s _{Microprocessor Supplies}
s _{Post Regulators for Switching Supplies}
s _{High Current Regulators}
s _{5V to 3.XXV for Pentium}^® _{Processors Operating}
at 90MHz to 166MHz and Beyond
s _{3.3V to 2.9V for Portable Pentium Processor}
s _PowerPC^TM _{Series Power Supplies}
DESCRIPTION
The LT ^®1581 is a 10A 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 430mV at 10A. 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 LT1581.
A remote SENSE pin is brought out. This feature virtually
eliminates output voltage variations due to load changes.
Typical load regulation for a load current step of 100mA to
10A, measured at the SENSE pin, is less than 1mV.
The LT1581 has fast transient response, equal to the
LT1584. On fixed voltage devices, the ADJUST pin is
brought out. A small capacitor on the ADJUST 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.
TYPICAL APPLICATION
2.5V Microprocessor Supply
3.3V
10A ₊
POWER
330µF
OUTPUT
OS-CON
LT1581-2.5
5V
0.2A
+
10µF
CONTROL
GND
TANT
SENSE
ADJ
0.1µF
2.5V/10A
+ 100µF TANT
AVX TPS
×7
1581 TA01
Dropout Voltage –
Minimum Power Voltage
0.8
INDICATES GUARANTEED TEST POINTS
0.7
0.6
0.5
DATA SHEET LIMIT
0.4
0.3
T_J = 125°C
0.2
T_J = 25°C
0.1
0
0 1 2 3 4 5 6 7 8 9 10
OUTPUT CURRENT (A)
1581 G03
1