© Semiconductor Components Industries, LLC, 2002

December, 2001 – Rev. 9

1

Publication Order Number:

CS51031/D

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

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

°C to 85°C

°C to 70°C

PGND

GND

CS

100

Ω

0.1

µF

CS

0.1

µF

470 pF

1.5 k

Ω

2.5 k

Ω

0.1

µF

100

µF × 2

3.3 V @ 3 A

L

4.7

µH

MBRS360

5.0 V–12 V

47

µF

IRF7416

Figure 1. Typical Application Diagram

95 Units/Rail

PIN CONNECTIONS

A

= Assembly Location

WL, L

= Wafer Lot

YY, Y

= Year

WW, W = Work Week

SO–8

D SUFFIX

CASE 751

1

8

1

51031

ALYW

8

MARKING

DIAGRAM

GND

CS

PGND

1

Device

Package

Shipping

ORDERING INFORMATION*

CS51031YD8

SO–8

95 Units/Rail

CS51031YDR8

2500 Tape & Reel

CS51031GD8

CS51031GDR8

2500 Tape & Reel

SO–8

SO–8

SO–8

*Additional ordering information can be found on

page 9 of this data sheet.

http://onsemi.com