SP6137 Datasheet, PDF (1/15 Pages) Sipex Corporation – Wide Input, 900KHz Synchronous PWM Controller

January 2009
SP6137
Wide Input, 900kHz Synchronous PWM Step Down
Controller
Rev. 2.0.0
GENERAL DESCRIPTION
The SP6137 is a 900kHz constant frequency,
voltage mode, synchronous PWM step down
controller optimized for high efficiency.
The SP6137 is adequately suited for split plane
applications utilizing a low power 5V rail to
power the controller circuitry, minimizing
power dissipation. Its wide input voltage range
of 3V to 15V allows for conversions from the
standard 3.3V, 5V, 9.6V and 12V power rails
to an output voltage adjustable down to 0.8V.
Developed around a wide bandwidth internal
amplifier, the SP6137 can accommodate type
II and type III compensation schemes.
Protection features include a programmable
UVLO, thermal shutdown and output short
circuit protection.
The SP6137 is part of a larger family of step
down controllers operating at various
switching frequencies up to 1300kHz and input
voltages up to 28V. Refer to Exar’s SP6132,
SP6132H, SP6134, SP6134H and SP6139 for
complete details.
The SP6137 is available in lead free, RoHS
compliant, space saving 10-pin MSOP
package.
APPLICATIONS
• 12V DPA
• Communications Systems
• Graphics Cards
FEATURES
• 2.5V to 20V Step Down Achieved Using
Dual Input
• On-Board 1.5Ω sink (2Ω source) NFET
Drivers
• Up to 10A Output Capability
• UVLO Detects Both VCC and VIN
• Short-Circuit Protection with Auto-
Restart
• Supports Type II or III Compensation
• Programmable Soft Start
• Fast Transient Response
• High Efficiency: Greater than 94%
• Non-synchronous Start-Up
• Small 10-Pin MSOP Package
• U.S. Patent #6,922,041
TYPICAL APPLICATION DIAGRAM
V_CC = 5V @ 30mA
RLF
3.0,5%
R3
221k, 1%
UV_IN
R4
100k, 1%
DBST
MBR0530
C_VCC
10μF
6.3V
GND 3
0.8V
C_VCC
Ceramic
8050
X5R
CF1
100pF
U1
1 _VCC
BST ¹⁰
2
SP6137
GL
GH
9
3 _GND
SWN ⁸
4 _VFB
SS ⁷
5 _{COMP UVIN} 6
CZ2 RZ2
820pF 40.2k, 1%
CP1
56pF
8765
QT
FDS6676S
4
14.5A, 6mΩ
123
CBST
0.1μF
C1
22μF
16V
C2
22μF
16V
C1, C2
Ceramic
1210
X5R
VIN
2.5V -20V
GND
R5
Bead
8765
QB
L1 SC5018-2R7M
2.7μH @ 12A
DCR=4.30mΩ
4
SS
123
FDS6676S
14.5A, 6.0mΩ
CSS
47nF
C3
47μF
6.3V
C4
47μF
6.3V
RZ3
4.64k, 1%
CZ3
220pF
V_OUT≤VIN
3.3V @ 10A
R1
68.1k, 1%
GND2
C3, C4
Ceramic
1210
X5R
R2
21.5k, 1%
Fig. 1: SP6137 Application Diagram
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
www.exar.com
Tel. [phone] – Fax. [phone]