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SP7650
Wide Input Voltage Range 3A, 300kHz, Buck Regulator
SP7650
FEATURES
■ 2.5V to 28V Step Down Achieved Using Dual Input
DFN PACKAGE
7mm x 4mm
■ Output Voltage down to 0.8V
■ 3A Output Capability
■ Built in Low RDSON Power Switches (40 mΩ typ)
■ Highly Integrated Design, Minimal Components
■ 300 kHz Fixed Frequency Operation
■ UVLO Detects Both VCC and VIN
P
P
GND
GND
GND
1
2
3
26
25
24
23
LX
LX
LX
TOP VIEW
Heatsink Pad 1
Connect to Lx
P
GND
4
5
LX
V
FB
22 V
CC
COMP
UVIN
GND
SS
21 GND
20 GND
6
7
Heatsink pad 2
Connect to GND
■ Over Temperature Protection
■ Short Circuit Protection with Auto-Restart
■ Wide BW Amp Allows Type II or III Compensation
■ Programmable Soft Start
8
9
19
18
GND
BST
V
IN 10
17
16
NC
LX
Heatsink pad 3
■ Fast Transient Response
V
V
V
IN 11
IN 12
Connect to V
IN
■ High Efficiency: Greater than 95% Possible
■ Asynchronous Start-Up into a Pre-Charged Output
■ Small 7mm x 4mm DFN Package
15 LX
14
LX
IN 13
Now Available in Lead Free Packaging
DESCRIPTION
The SP7650 is a synchronous step-down switching regulator optimized for high efficiency. The part is designed to be
especially attractive for dual supply, 12V or 24V distributed power systems step down with 5V used to power the
controller.ThislowerVCC voltageminimizespowerdissipationinthepartandisusedtodrivethetopswitch.TheSP7650
is designed to provide a fully integrated buck regulator solution using a fixed 300kHz frequency, PWM voltage mode
architecture. Protection features include UVLO, thermal shutdown and output short circuit protection. The SP7650 is
available in the space saving DFN package.
TYPICAL APPLICATION CIRCUIT
U1
SP7650
L1
1
26
PGND
PGND
LX
LX
VOUT
3.3V
0-3A
2.2uH, Irate=4.78A
2
3
25
24
RZ2
CZ2
RZ3
PGND
GND
LX
LX
15k,1%
7.15k,1%
1,000pF
C3
4
5
23
22
R1
47uF
6.3V
CP1
68.1k,1%
VFB
VCC
CZ3
22pF
150pF
6
7
21
20
COMP
UVIN
GND
GND
CVCC
2.2uF
CF1
100pF
ENABLE
8
9
19
18
GND
SS
GND
BST
DBST
RSET
21.5k,1%
(note 2)
10
17
16
SD101AWS
CSS
VIN
VIN
NC
LX
47nF
11
CBST
6800pF
12
13
15
14
VIN
VIN
LX
LX
VIN
12V
+5V VCC
fs=300Khz
C1
Notes:
22uF
1. U1 Bottom-Side Layout should
16V
has three contacts isolated from
one another Vin SWNODE and GND
GND
2. RSET=54.48/(Vout-0.8V)
(KOhm)
Date: 08/24/04
SP7650 Wide Input Voltage Range 3A, 300kHz, Buck Regulator
© Copyright 2004 Sipex Corporation
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