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SP7655
Wide Input Voltage Range 8A, 300kHz, Buck Regulator
SP7655
FEATURES
■ 2.5V to 28V Step Down Achieved Using Dual Input
DFN PACKAGE
7mm x 4mm
■ Output Voltage down to 0.8V
■ 8A Output Capability
■ Built in Low RDSON Power Switches (15 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
■ Fast Transient Response
Heatsink pad 3
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 SP7655 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.TheSP7655
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 SP7655 is
available in the space saving DFN package.
TYPICAL APPLICATION CIRCUIT
U1
SP7655
L1
1
2
3
4
26
25
24
23
PGND
PGND
PGND
GND
LX
LX
LX
LX
VOUT
3.30V
0-6A
2.2uH, Irate=8A
RZ2
CZ2
RZ3
15k,1%
7.15k,1%
1,000pF
C3
R1
47uF
6.3V
CP1
5
6
7
8
9
22
21
20
19
18
68.1k,1%
VFB
VCC
CZ3
22pF
150pF
COMP
UVIN
GND
SS
GND
GND
GND
BST
NC
CVCC
2.2uF
CF1
ENABLE
100pF
DBST
RSET
21.5k,1%
(note 2)
10
17
16
15
14
SD101AWS
CSS
VIN
47nF
11
12
13
VIN
VIN
VIN
LX
LX
LX
CBST
68,00pF
VIN
+5V VCC
12V
fs=300Khz
C1
22uF
16V
C4
Notes:
1. U1 Bottom-Side Layout should
has three contacts isolated from
one another Vin SWNODE and GND
22uF
16V
GND
2. RSET=54.48/(Vout-0.8V)
(KOhm)
Date: 08/17/04
SP7655 Wide Input Voltage Range 8A, 300kHz, Buck Regulator
© Copyright 2004 Sipex Corporation
1