Linear Fet Controller
POWER MANAGEMENT
Description
The SC1548 is a power supply controller designed to
provide a simple single regulated power supply with over
current protection. It is part of Semtechs SmartLDO
family of products. The SC1548 can provide a 1.818V
power supply for the I/O plane or 1.515V for GTL+ / AGP
from either 3.3V or 2.5V. An adjustable option allows
generation and control of any voltage from 1.263V up to
5V.
SC1548 features include tight output voltage regulation,
an enable control and over current protection. Over
current protection is provided by feedback to the sense
pin. If the output drops below 50% of the nominal
output voltage (typical) for greater than 4ms (typical), the
output will be shut down.
The SC1548 is available in a tiny 5-pin SOT-23 surface
mount package.
SC1548
Features
u
± 2.5% output accuracy over line, load and
u
u
u
u
u
u
u
u
temperature
1.515V, 1.818V and adjustable output voltage
options available
Enable control
Over current protection
5-pin SOT-23 package
Applications
Motherboards
Graphics cards
Microcontrollers
Simple power supplies
Typical Application Circuit
Fixed Output Voltage Versions
1.818V OUT
+
C1
100uF
+
C2
100uF
Q1
IRL530N
3.3V IN
12V IN
+
C3
22uF
1
2
3
U1
SNS
GND
DRV
IN
4
C4
0.1uF
EN
5
ENABLE
SC1548CSK-1.8
Adjustable Output Voltage Version
Q1
IRL530N
3.3V IN
12V IN
2.5V OUT
R1
97.6
+
C1
100uF
+
C2
100uF
+
C3
22uF
U1
1
2
ADJ
GND
DRV
IN
4
C4
0.1uF
EN
5
ENABLE
R2
100
3
SC1548CSK
Revision 1, January 2001
1
www.semtech.com
SEMTECH [ SEMTECH CORPORATION ]
