FAN1581 Datasheet, PDF (1/13 Pages) Fairchild Semiconductor – 5A Adjustable/Fixed Ultra Low Dropout Linear Regulator

www.fairchildsemi.com
FAN1581
5A Adjustable/Fixed Ultra Low Dropout
Linear Regulator
Features
• Ultra Low dropout voltage, 0.4V typical at 5A
• 1.2V Versions available for GTL termination
• Remote sense operation
• Fast transient response
• Load regulation: 0.05% typical
• 0.5% typical initial accuracy
• On-chip thermal limiting
• TO-263, TO-252 and TO-220 packages
Applications
• Support of GTL+ bus supply
• Low voltage logic supply
• Embedded Processor supplies
• Split plane regulator
• 2.5V, and 1.8V Logic Families
• DDR Termination Supply
Description
The FAN1581, FAN1581-1.2, FAN1581-1.5, and FAN1581-
2.5 are ultra-low dropout regulators with 5A output current
capability. These devices have been optimized for low volt-
age applications including V_TT bus termination, where tran-
sient response and minimum input voltage are critical. The
FAN1581 is ideal for low voltage microprocessor applica-
tions requiring a regulated output from 1.3V to 5.7V with a
power input supply of 1.75V to 6.5V. The FAN1581-1.5
offers fixed 1.5V with 5A current capabilities for GTL+ bus
V_TT termination. Additionally, the FAN1581-1.2 offers fixed
1.2V output for CPU Bus termination. The FAN1581-2.5
offers fixed 2.5V with 5A current capability for logic IC
operation and processors while minimizing the overall power
dissipation.
Current limit ensures controlled short-circuit current. On-chip
thermal limiting provides protection against any combination
of overload and ambient temperature that would create exces-
sive junction temperatures.
The FAN1581 series regulators are available in the 5-pin
TO-263, TO-252 and TO-220 packages.
Typical Applications
V_IN = 3.3V
+
10µF
V_CNTL = 5V
+
1µF
V_IN
V_SENSE
FAN1581
V_CNTL
V_OUT
Adj
V_IN = 3.3V
+
10µF
V_CNTL = 5V
+
1µF
V_IN
V_SENSE
FAN1581-1.2
V_CNTL
V_OUT
Gnd
V_IN = 3.3V
+
10µF
124Ω
86.6Ω
2.1V at 5A
+
22µF
V_CNTL = 5V
+
1µF
V_IN = 5.75V
+
10µF
V_CNTL = 12V
+
1µF
V_IN
V_SENSE
FAN1581–2.5
V_OUT
V_CNTL
GND
V_IN
V_SENSE
FAN1581
V_CNTL
V_OUT
Adj
1.2V at 5A
22µF
2.5V at 5A
+
22µF
124Ω
5V at 5A
+
22µF
374Ω
Pentium is a registered trademark of Intel Corporation. PowerPC is a trademark of IBM Corporation.
REV. 1.2.0 11/6/03