POWER MANAGEMENT
Description
The SC1566 is a high performance positive voltage
regulator designed for use in applications requiring very
low dropout voltage at up to 3 Amps. Since it has
superior dropout characteristics compared to regular
LDOs, it can be used to supply 2.5V on motherboards or
2.8V on peripheral cards from the 3.3V supply thus
allowing heat sink size reduction or elimination.
Additionally, the five pin versions of SC1566 have an
enable pin, to further reduce power dissipation while shut
down. The SC1566 provides excellent regulation over
variations in line, load and temperature.
The SC1566 is available as three terminal fixed output
voltage and five terminal fixed or adjustable output
voltage devices with enable. Two package options are
available: TO-263 and TO-220.
Very Low Dropout
3.0 Amp Regulator With Enable
Features
u
350mV dropout @ 3A
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Adjustable output from 1.2V to 4.8V
u
2.5V and 1.8V options (5 pin parts also adjustable
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u
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u
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externally using resistors)
Over current and over temperature protection
Enable pin
10µA quiescent current in shutdown
Low reverse leakage (output to input)
Full industrial temperature range
TO-220 and TO-263 packages
SC1566
Applications
Battery powered systems
Motherboards and notebook computers
Peripheral cards
Network cards
Set top boxes
Medical equipment
Typical Application Circuits
(1)(2)
U1
SC1566I5T-2.5
VIN
ENABLE
1
2
VIN
EN
VO
ADJ
5
4
VO = See equation below
GND
3
R1
VO
=
C2
R2
C1
1.200 (R1
+
R2)
Volts
R2
U1
SC1566I5T-2.5
VIN
ENABLE
C1
1
2
VIN
EN
VO
ADJ
5
4
C2
VO = 2.5V
GND
3
U1
SC1566IT-1.8
VIN
1
VIN
VO
3
VO = 1.8V
GND
C1
2
C2
Notes:
(1) Maximum VO setpoint for 1.8V parts = 5.4V
(2) This device is designed to operate with
ceramic input and output capacitors
www.semtech.com
Revision 1, January 2001
1
SEMTECH [ SEMTECH CORPORATION ]
