High Performance Wide Input Range
Dual Synchronous Buck Controller
POWER MANAGEMENT
Description
SC2442 and SC2442H are high performance dual buck
converter controllers that can be configured for a variety
of synchronous buck applications where efficiency is most
important. Both converters are synchronized to prevent
beat frequencies. The dual buck converters are also
operated out of phase reducing input ripple, allowing for
fewer input capacitors.
High frequency operation up to 1.1 MHz reduces the size
of output inductors and capacitors. The controller has
separate power pins for both VCC and GND to improve
noise immunity. The VCC supplies can be regulated to 7V
using an external PNP transistor. Other features include:
bootstrapping for high side drive supplies, asynchronous
mode start up, power up sequencing to prevent latch-
ups, individual soft start for each convertor, bootstrapped
drivers for high side N-channel MOSFETs, input side
current sensing, dual mode current limit with hiccup,
enable and external frequency synchronization.
The SC2442 operates over the range of 4.75V to 30V
and SC2442H operates over the range of 4.75V to 36V.
SC2442/H
Features
Dual output controller
Asynchronous start up mode
Power up sequencing to prevent latch-ups
Out of phase operation for low input ripple
Over current protection
Output down to 0.75V
Wide input range, 4.75 to 30V for SC2442 and
4.75 to 36V for SC2442H
Vcc regulator with external PNP transistor
Programmable clock frequency up to 1.1MHz
Two synchronous bucks for high efficiency at high
current
–40 to +125 Deg C operating temperature
Small package TSSOP-24
Fully WEEE and RoHS Compliant
Applications
Point of load converter applications
DSL applications with multiple output voltages
Power management for mixed signal applications
Cable modems and set top boxes.
Typical Application Circuit
VIN+
MAX 30V/36V (H)
R1
R2
R3
Q5
R9
C6
C7
OC1
OC2
R4
Q1
R5
L1
Q3
R7
C2
C1
VOUT1
RTN
3
2
C4
AVCC
PVCC
R10
C5
1
13
7
18
23
SS1
C8
SS2
C9
OSC
R12
6
5
19
20
22
VI N
BD I
AVC C
U1
OC 1
OC 2
G D 1H
4
21
9
11
16
14
10
8
15
17
12
24
D1
D2
Q2
R6
L2
Q4
R8
C3
RTN
VOUT2
SS1
SS2
ROS C
FB1
E A1
FB2
E A2
SC2442ITSTR
P VC C
G D 1L
G D 2H
G D 2L
PH1
BS T 1
PH2
BS T 2
P G ND
AG ND
PH1
BST1
PH2
BST2
C16
C15
RTN
R13
R14
S YN C /E N
R15
R16
RTN
R11
C10
C11
EA2
C13
FB2
RTN
R17
C12
R18
ENA
FB1
Revision: June, 2007
1
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