NCP1271
Soft-Skipt Mode Standby
PWM Controller with
Adjustable Skip Level and
External Latch
http://onsemi.com
The NCP1271 represents a new, pin to pin compatible, generation
of the successful 7−pin current mode NCP12XX product series. The
controller allows for excellent stand by power consumption by use of
its adjustable Soft−Skip mode and integrated high voltage startup
FET. This proprietary Soft−Skip also dramatically reduces the risk of
acoustic noise. This allows the use of inexpensive transformers and
capacitors in the clamping network. Internal frequency jittering,
ramp compensation, timer−based fault detection and a latch input
make this controller an excellent candidate for converters where
ruggedness and component cost are the key constraints.
MARKING
DIAGRAMS
8
SOIC−7
D SUFFIX
CASE 751U
1271x
ALYWG
G
1
1271Pxxx
AWL
YYWWG
PDIP−7 VHVIC
P SUFFIX
CASE 626B
Features
• Fixed−Frequency Current−Mode Operation with Ramp
Compensation and Skip Cycle in Standby Condition
• Timer−Based Fault Protection for Improved Overload Detection
• “Soft−Skip Mode” Technique for Optimal Noise Control in Standby
• Internal High−Voltage Startup Current Source for Lossless Startup
• "5% Current Limit Accuracy over the Full Temperature Range
• Adjustable Skip Level
• Internal Latch for Easy Implementation of Overvoltage and
Overtemperature Protection
• Frequency Jittering for Softened EMI Signature
• +500 mA/−800 mA Peak Current Drive Capability
• Sub−100 mW Standby Power can be Achieved
• Pin−to−Pin Compatible with the Existing NCP120X Series
• This is a Pb−Free Device
8
1
1
x
= A or B
A= 65 kHz
B= 100 kHz
xxx
A
= Device Code: 65, 100
= Assembly Location
L, WL = Wafer Lot
Y, YY = Year
W, WW = Work Week
G or G = Pb−Free Package
(Note: Microdot may be in either location)
PIN CONNECTIONS
1
2
3
4
8
Skip/latch
FB
HV
Typical Applications
• AC−DC Adapters for Notebooks, LCD Monitors
• Offline Battery Chargers
• Consumer Electronic Appliances STB, DVD, DVDR
6
5
CS
V
CC
Drv
GND
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 19 of this data sheet.
*For additional information on our Pb−Free strategy and soldering details, please
downloadthe ON Semiconductor Soldering and Mounting Techniques Reference
Manual, SOLDERRM/D.
©
Semiconductor Components Industries, LLC, 2009
1
Publication Order Number:
September, 2009 − Rev. 6
NCP1271/D
ETC [ ETC ]
