CS51031
Fast PFET 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
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 start up. The short
circuit protection timer significantly reduces the duty cycle to
approximately 1/30 of its cycle during short circuit conditions.
The CS51031 is available in an 8 Lead SO plastic package.
Features
•
1.0 A Totem Pole Output Driver
•
High Speed Oscillator (700 kHz max)
•
No Stability Compensation Required
•
Lossless Short Circuit Protection
•
V
CC
Monitor
•
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
5.0 V–12 V
http://onsemi.com
MARKING
DIAGRAM
8
8
1
SO–8
D SUFFIX
CASE 751
1
A
WL, L
YY, Y
WW, W
= Assembly Location
= Wafer Lot
= Year
= Work Week
51031
ALYW
PIN CONNECTIONS
V
GATE
PGND
C
OSC
GND
1
V
C
CS
V
CC
V
FB
ORDERING INFORMATION*
C
IN
47
µF
MP
1
IRF7416
Device
CS51031YD8
CS51031YDR8
CS51031GD8
CS51031GDR8
Package
SO–8
SO–8
SO–8
SO–8
Shipping
95 Units/Rail
2500 Tape & Reel
95 Units/Rail
2500 Tape & Reel
V
GATE
V
GATE
V
C
MBRS360
D
1
CS51031
PGND
CS
RV
CC
100
Ω
V
CC
CV
CC
0.1
µF
R
B
2.5 kΩ
V
O
3.3 V @ 3 A
C
OSC
470 pF
C
OSC
CS
0.1
µF
*Additional ordering information can be found on
page 9 of this data sheet.
L
4.7
µH
GND
V
FB
R
A
1.5 kΩ
C
RR
0.1
µF
C
O
100
µF ×
2
Figure 1. Typical Application Diagram
©
Semiconductor Components Industries, LLC, 2002
1
December, 2001 – Rev. 9
Publication Order Number:
CS51031/D
ONSEMI [ ON SEMICONDUCTOR ]
