© Semiconductor Components Industries, LLC, 2016
January, 2016 − Rev. 7
1 Publication Order Number:
NCP1252/D
NCP1252
Current Mode PWM
Controller for Forward and
Flyback Applications
The NCP1252 controller offers everything needed to build cost−
effective and reliable ac−dc switching supplies dedicated to ATX
power supplies. Thanks to the use of an internally fixed timer,
NCP1252 detects an output overload without relying on the auxiliary
Vcc. A Brown−Out input offers protection against low input voltages
and improves the converter safety. Finally a SOIC−8 package saves
PCB space and represents a solution of choice in cost sensitive project.
Features
• Peak Current Mode Control
• Adjustable Switching Frequency up to 500 kHz
• Jittering Frequency ±5% of the Switching Frequency
• Latched Primary Over Current Protection with 10 ms Fixed Delay
• Delay Extended to 150 ms in E Version
• Delayed Operation Upon Start−up via an Internal Fixed Timer
(A, B and C versions only)
• Adjustable Soft−start Timer
• Auto−recovery Brown−Out Detection
• UC384X−like UVLO Thresholds
• Vcc Range from 9 V to 28 V with Auto−recovery UVLO
• Internal 160 ns Leading Edge Blanking
• Adjustable Internal Ramp Compensation
• +500 mA / –800 mA Source / Sink Capability
• Maximum 50% Duty Cycle: A Version
• Maximum 80% Duty Cycle: B Version
• Maximum 65% Duty Cycle: C Version
• Maximum 47.5% Duty Cycle: D & E Versions
• Ready for Updated No Load Regulation Specifications
• SOIC−8 and PDIP−8 Packages
• These are Pb−Free Devices
Typical Applications
• Power Supplies for PC Silver Boxes, Games Adapter...
• Flyback and Forward Converter
SOIC−8
CASE 751
SUFFIX D
PIN CONNECTIONS
MARKING DIAGRAMS
(Top View)
OFFLINE CONTROLLER
www.onsemi.com
1
8
x = A, B, C, D or E
A = Assembly Location
L, WL = Wafer Lot
Y, YY = Year
W, WW = Work Week
G or G = Pb−Free Package
1252x
ALYWX
G
1
8
See detailed ordering and shipping information in the package
dimensions section on page 18 of this data sheet.
ORDERING INFORMATION
SS
V
CC
DRV
GND
FB
BO
CS
RT
1
PDIP−8
CASE 626
SUFFIX P
1252AP
AWL
YYWWG
