SP6138 Datasheet, PDF (1/17 Pages) Sipex Corporation – Synchronous Buck Controller

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Synchronous Buck Controller
SP6138
FEATURES
16 15 14 13
■ 5V to 24V Input step down converter
■ Up to 3A output in a small form factor
■ Highly integrated design, minimal components
GL ¹
■ UVLO Detects Both V_CC and V_IN
PGND 2
SP6138
12 GH
11 _SWN
■ Overcurrent circuit protection with auto-restart
■ Power Good Output, ENABLE Input
GND ³
■ Maximum Controllable Duty Cycle Ratio up to 92% _{VFB 4}
■ Wide BW amp allows Type II or III compensation
16 Pin QFN
3mm x 3mm
10 _ISP
9 _ISN
■ Programmable Soft Start
■ Fast Transient Response
5678
■ Available in 16-Pin QFN package
■ External Driver Enable/Disable
■ U.S. Patent #6,922,041
Now Available in Lead Free Packaging
DESCRIPTION
The SP6138 is a synchronous step-down switching regulator controller optimized for small
footprint. The part is designed to be especially attractive for single supply step down con-
version from 5V to 24V. The SP6138 is designed to drive a pair of external NFETs using a
fixed 2.5 MHz frequency, PWM voltage mode architecture. Protection features include UVLO,
thermal shutdown, output short circuit protection, and overcurrent protection with auto restart.
The device also features a PWRGD output and an enable input. The SP6138 is available in
a space saving 16-pin QFN and offers excellent thermal performance.
TYPICAL APPLICATION CIRCUIT
C5
0.1uF
DBST
CVCC
4.7uF
SD101AWS
VIN
BST
R3 10KΩ
POWERGOOD
NC
ENABLE
VCC
GH
PWRGD
SWN
UVIN
EN ^SP6138
GND
GL
CF1
18pF
PGND
CP1
6 pF
COMP
ISP
VFB
ISN
SS
CZ3
47pF
CZ2
100pF
RZ2
54.9KΩ
CBST
0.1uF
MT/MB, Si7214DN
47 mΩ, 30V
(Co-Packaged FETs)
COOPER, SD25-2R2
2.2uH, 2.8A, 31mΩ
CSS
47nF
RZ3
1KΩ
CSP
6.8nF
RS1
1KΩ
RS2
1KΩ
RS3
4.99KΩ
CS
0.1uF
C1
4.7uF
VIN
12V
GND
VOUT
3.3V
C2 0-2A
22uF
GND
R1
68.1KΩ, 1%
R2
21.5KΩ, 1%
Oct 24-06 Rev J
Note: Die-attach paddle is connected to GND
SP6138 Synchronous Buck Controller

© 2006 Sipex Corporation