SC1102 Datasheet, PDF (1/10 Pages) Semtech Corporation – SYNCHRONOUS DC/DC CONTROLLER FOR DISTRIBUTED POWER SUPPLY APPLICATIONS

SYNCHRONOUS DC/DC CONTROLLER FOR
SC1102
DISTRIBUTED POWER SUPPLY APPLICATIONS
September 5, 2000
TEL:[phone] FAX:[phone] WEB:http://www.semtech.com
DESCRIPTION
FEATURES
The SC1102 is a low-cost, full featured, synchronous
voltage-mode controller designed for use in single
ended power supply applications where efficiency is of
primary concern. Synchronous operation allows for the
elimination of heat sinks in many applications. The
SC1102 is ideal for implementing DC/DC converters
needed to power advanced microprocessors in low
cost systems, or in distributed power applications
where efficiency is important. Internal level-shift, high-
side drive circuitry, and preset shoot-thru control, al-
lows the use of inexpensive N-channel power switches.
SC1102 features include temperature compensated
voltage reference, triangle wave oscillator and current
sense comparator circuitry. Power good signaling,
shutdown, and over voltage protection are also pro-
vided.
The SC1102 operates at a fixed 200kHz, providing an
optimum compromise between efficiency, external
component size, and cost.
• 1.265V Reference available
• Synchronous operation
• Over current fault monitor
• On-chip power good and OVP functions
• Small size with minimum external components
• Soft Start
• R_DS(ON) Current sensing
APPLICATIONS
• Microprocessor core supply
• Low cost synchronous applications
• Voltage Regulator Modules (VRM)
ORDERING INFORMATION
DEVICE⁽¹⁾
PACKAGE
SC1102CSTR SO-14
TEMP. RANGE (T_J)
0 - 125°C
SC1102EVB
Evaluation Board
APPLICATION CIRCUIT
Note:
(1) Only available in tape and reel packaging. A reel
contains 2500 devices.
Typical Distributed Power Supply
+5V
R1
R2
1k
PWRGD
OVP
C1
0.1
C2
0.1
R4
10
U1
SC1102
1 _VCC
GND ¹⁴
2 _PWRGD
SS/SHDN ¹³
R3
1k
3 _OVP
VREF ¹²
4 _OCSET
SENSE ¹¹
5 _PHASE
D1
MBR0520 6 _DRVH
BSTH ¹⁰
BSTL ⁹
7 _PGND
DRVL ⁸
C3
0.1
SHDN
VREF
+12V
C4
1.0
R5
3.9
R6
2.2
+
C5
C6
C7
C8
Vin 5V
10.0
680/6.3V 680/6.3V 680/6.3V
_
Q1
L1
STP40NE
2uH
Q2
STP40NE
R8
124*
R7
127
C9
180/4V
C10
180/4V
C11
180/4V
C12
180/4V
+
C13
180/4V
Vout=2.5V*
_
NOTE:
*) Vout = 1.265 x (1+R8/R7)
Figure 1.
© 2000 SEMTECH CORP.
1
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