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The CS5151 is a 4-bit nonsyn-
chronous N-Channel buck con-
troller. It is designed to provide
unprecedented transient response
for today’s demanding high-densi-
ty, high-speed logic. The regulator
operates using a proprietary control
method, which allows a 100ns
response time to load transients.
The CS5151 is designed to operate
over a 4.25-16V range (V
CC
) using
12V to power the IC and 5V as the
main supply for conversion.
The CS5151 is specifically designed
to power Pentium
processors with
MMX Technology and other high
performance core logic. It includes
the following features: on board,
4-bit DAC, short circuit protection,
1.0% output tolerance, V
CC
monitor,
and programmable soft start capa-
bility. The CS5151 is upwards com-
patible with the 5-bit CS5156, allow-
ing the mother board designer the
capability of using either the
CS5151 or the CS5156 with no
change in layout. The CS5151 is
available in 16 pin surface mount
and DIP packages.
Features
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N-Channel Design
Excess of 1MHz Operation
100ns Transient Response
4-Bit DAC
Upward Compatible with
5-Bit CS5155/5156 and
Adjustable CS5120/5121
30ns Gate Rise/Fall Times
1% DAC Accuracy
5V & 12V Operation
Remote Sense
Programmable Soft Start
Lossless Short Circuit
Protection
V
CC
Monitor
Adaptive Voltage
Positioning
V
2
Control Topology
Current Sharing
Overvoltage Protection
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Package Options
CPU 4-Bit Nonsynchronous Buck Controller
CS5151
Description
Application Diagram
1
V
ID0
V
ID1
V
ID2
V
ID3
SS
NC
C
OFF
V
FFB
V
FB
COMP
LGnd
V
CC1
NC
PGnd
V
GATE
V
CC2
16 Lead SO Narrow & PDIP
1
Switching Power Supply for core logic - Pentium
processor with MMX Technology
0.33
μ
F
V
ID0
V
ID1
V
ID2
V
ID3
V
ID0
V
ID1
V
ID2
V
ID3
V
CC1
SS
C
OFF
LGnd
V
FB
V
FFB
COMP
IRL3103
0.1
μ
F
12V
5V
2
μ
H
2.1V to 3.5V @ 13A
V
CC2
V
GATE
PGnd
1200
μ
F/16V x 3
AlEl
3.3k
0.1
μ
F
1200
μ
F/16V x 5
AlEl
100pF
330pF
CS5151
MBR735
3
1,2
V
2
is a trademark of Switch Power, Inc.
Pentium is a registered trademark and MMX is a trademark of Intel Corporation.
C
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
A
Company
Rev. 1/5/99