© Semiconductor Components Industries, LLC, 2006

July, 2006 − Rev. 4

1

Publication Order Number:

CS2842A/D

CS2842A, CS3842A,

CS2843A, CS3843A

Off−Line Current Mode

PWM Control Circuit with

Undervoltage Lockout

The CS284XA, CS384XA provides all the necessary features to

implement off−line fixed frequency current−mode control with a

minimum number of external components.

The CS384XA family incorporates a new precision

temperature−controlled oscillator with an internally trimmed

discharge current to minimize variations in frequency. A precision

duty−cycle clamp eliminates the need for an external oscillator when a

50% duty−cycle is used. Duty−cycles greater than 50% are also

output stage is enabled. Ion implant resistors provide tighter control of

undervoltage lockout.

Other features include low startup current, pulse−by−pulse current

limiting, and a high−current totem pole output for driving capacitive

loads, such as the gate of power MOSFET. The output is LOW in the

off state, consistent with N−channel devices.

The CS384XA series of current−mode control ICs are available in

8 and14 lead packages for surface mount (SO) applications as well as

8 lead PDIP packages.

Features

http://onsemi.com

x

= 2 or 3

y

= 2 or 3

A

= Assembly Location

WL, L

= Wafer Lot

YY, Y

= Year

WW, W = Work Week

DIP−8

N SUFFIX

CASE 626

1

8

SO−8

D SUFFIX

CASE 751

1

8

SO−14

D SUFFIX

CASE 751A

1

14

1

8

x84yA

AWL

YYWW

MARKING

DIAGRAM

1

x84yA

ALYWX

8

1

CSx84yA

AWLYWW

14

See detailed ordering and shipping information in the package

dimensions section on page 8 of this data sheet.

ORDERING INFORMATION