SC4607
Very Low Input, MHz Operation,
High Efficiency Synchronous Buck
POWER MANAGEMENT
Description
Features
The SC4607 is a voltage mode step down (buck) regula-
tor controller that provides accurate high efficiency power
conversion from an input supply range of 2.25V to 5.5V.
The SC4607 is capable of producing an output voltage
as low as 0.5V and has a maximum duty cycle of 97%. A
high level of integration reduces external component
count, and makes it suitable for low voltage applications
where cost, size, and efficiency are critical.
Asynchronous start up
BiCMOS voltage mode PWM controller
Operation of frequency to 1MHz
2.25V to 5.5V input voltage range
Output voltages as low as 0.5V
+/-1% reference accuracy
Sleep mode (Icc = 10µA typ)
Adjustable lossless short circuit current limiting
Combination pulse by pulse & hiccup mode
current limit
The SC4607 drives external, N-channel MOSFETs with a
peak gate current of 1A. The SC4607 prevents shoot
through currents by offering nonoverlap protection for
the gate drive signals of the external MOSFETs. The
SC4607 features lossless current sensing of the voltage
drop across the drain to source resistance of the high
side MOSFET during its conduction period.
High efficiency synchronous switching
Up to 97% duty cycle
1A peak current driver
10-pin MSOP package
Applications
Distributed power architecture
The quiescent supply current in sleep mode is typically
lower than 10µA. A 1.2ms soft start is internally provided Servers/workstations
to prevent output voltage overshoot during start-up.
Local microprocessor core power supplies
DSP and I/O power supplies
The SC4607 is an ideal choice for converting 2.5V, 3.3V,
5V or other low input supply voltages. It’s available in 10
pin MSOP package
Battery-powered applications
Telecommunications equipment
Data processing applications
Typical Application Circuit
Vin = 2.25V - 5.5V
C10
C11
C12
D2
1u
22u
22u
C71
220u
M1
M2
R13
1
C14
0.1u
R6
0
R3
U1
1
2
3
4
5
10
9
BST
DRVH
PHASE
DRVL
GND
L1
C3
4.7u
Vout = 1.5V (as low as 0.5V * ) / 12A
VCC
ISET
COMP
1.8u
8
7
C6
C5
C4
C9
4.7n
C20
560pF
2.2n
6
22u
C2
330u
C1
22u
R7
FS/SYNC VSENSE
R5
0
10k
180p
R8
SC4607
200
R1
14.3k
R9
4.99k
*External components can be modified to provide a Vout as low as 0.5V
Revision: June 1, 2005
1
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