© Semiconductor Components Industries, LLC, 2014
December, 2014 − Rev. 1
1 Publication Order Number:
NCP1253/D
NCP1253
Current-Mode PWM
Controller for Off-line
Power Supplies
The NCP1253 is a highly integrated PWM controller capable of
delivering a rugged and high performance offline power supply in a
tiny TSOP−6 package. With a supply range up to 28 V, the controller
hosts a jittered 65 kHz or 100 kHz switching circuitry operated in peak
current mode control. When the power on the secondary side starts to
decrease, the controller automatically folds back its switching
frequency down to a minimum level of 26 kHz. As the power further
goes down, the part enters skip cycle while limiting the peak current.
To avoid sub harmonic oscillations in CCM operation, adjustable
slope compensation is available via the series inclusion of a simple
resistor in the current sense signal.
Besides the auto−recovery timer−based short−circuit protection, an
Over Voltage Protection on the V
CC
pin protects the whole circuitry in
case of optocoupler destruction or adverse open loop operation.
Features
• Fixed−Frequency 65 kHz or 100 kHz Current−Mode Control
Operation
• Frequency Foldback Down to 26 kHz and Skip−Cycle in Light Load
Conditions
• Adjustable Ramp Compensation
• Internally Fixed 4 ms soft−start
• Timer−based Auto−Recovery or Latched Short−Circuit Protection
• Frequency Jittering in Normal and Frequency Foldback Modes
• Latched OVP on V
CC
• Up to 28 V V
CC
Operation
• Extremely Low No−load Standby Power
• These are Pb−Free Devices
Typical Applications
• Ac−dc Converters for TVs, Set−top Boxes and Printers
• Offline Adapters for Notebooks and Netbooks
PIN CONNECTIONS
1
3
CS
GND
2
NC
4
DRV
6
(Top View)
5
V
CC
TSOP−6
CASE 318G
STYLE 13
MARKING
DIAGRAM
FB
www.onsemi.com
(Note: Microdot may be in either location)
1
53xAYWG
G
1
53 = Specific Device Code
x = A, 2, C, or D
A = Assembly Location
Y = Year
W = Work Week
G = Pb−Free Package
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
ORDERING INFORMATION
