CS51031
Fast P−Ch FET
Buck Controller
The CS51031 is a switching controller for use in DC−DC
converters. It can be used in the buck topology with a minimum
number of external components. The CS51031 consists of a V
CC
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monitor for controlling the state of the device, 1.0 A power driver for
controlling the gate of a discrete P−Channel transistor, fixed frequency
oscillator, short circuit protection timer, programmable Soft−Start,
precision reference, fast output voltage monitoring comparator, and
output stage driver logic with latch.
The high frequency oscillator allows the use of small inductors and
output capacitors, minimizing PC board area and systems cost. The
programmable Soft−Start reduces current surges at startup. The short
circuit protection timer significantly reduces the duty cycle to
approximately 1/30 of its cycle during short circuit conditions.
8
1
SOIC−8
D SUFFIX
CASE 751
Features
• 1.0 A Totem Pole Output Driver
• High Speed Oscillator (700 kHz max)
• No Stability Compensation Required
• Lossless Short Circuit Protection
MARKING DIAGRAM
8
• V Monitor
CC
51031
ALYWx
G
• 2.0% Precision Reference
• Programmable Soft−Start
• Wide Ambient Temperature Range:
♦ Industrial Grade: −40°C to 85°C
♦ Commercial Grade: 0°C to 70°C
1
• Pb−Free Packages are Available
51031 = Device Code
A
L
= Assembly Location
= Wafer Lot
5.0 V−12 V
Y
W
x
= Year
= Work Week
= Continuation of Device Code
x = Y or G
= Pb−Free Package
C
47 mF
IN
MP
1
G
IRF7416
V
GATE
MBRS360
V
V
C
GATE
PIN CONNECTIONS
D
1
PGND
CS
1
RV
100 W
V
V
CC
GATE
C
CS
0.1 mF
PGND
CS
L
C
OSC
V
CC
CV
0.1 mF
4.7 mH
CC
C
V
CC
V
FB
OSC
C
OSC
GND
470 pF
R
B
GND
V
FB
V
O
2.5 kW
3.3 V @ 3 A
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
C
0.1 mF
RR
C
O
R
A
100 mF × 2
1.5 kW
Figure 1. Typical Application Diagram
©
Semiconductor Components Industries, LLC, 2005
1
Publication Order Number:
October, 2005 − Rev. 11
CS51031/D