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NCP1253 Datasheet, PDF (1/15 Pages) ON Semiconductor – Current-Mode PWM Controller for Off-line Power Supplies | |||
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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 TSOPâ6 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 autoârecovery timerâbased shortâcircuit protection, an
Over Voltage Protection on the VCC pin protects the whole circuitry in
case of optocoupler destruction or adverse open loop operation.
Features
⢠FixedâFrequency 65 kHz or 100 kHz CurrentâMode Control
Operation
⢠Frequency Foldback Down to 26 kHz and SkipâCycle in Light Load
Conditions
⢠Adjustable Ramp Compensation
⢠Internally Fixed 4 ms softâstart
⢠Timerâbased AutoâRecovery or Latched ShortâCircuit Protection
⢠Frequency Jittering in Normal and Frequency Foldback Modes
⢠Latched OVP on VCC
⢠Up to 28 V VCC Operation
⢠Extremely Low Noâload Standby Power
⢠These are PbâFree Devices
Typical Applications
⢠Acâdc Converters for TVs, Setâtop Boxes and Printers
⢠Offline Adapters for Notebooks and Netbooks
http://onsemi.com
1
TSOPâ6
CASE 318G
STYLE 13
MARKING DIAGRAM
53xAYWG
G
1
53
= Specific Device Code
x
= A, 2, C, or D
A
= Assembly Location
Y
= Year
W
= Work Week
G
= PbâFree Package
(Note: Microdot may be in either location)
PIN CONNECTIONS
GND 1
6 DRV
FB 2
NC 3
5 VCC
4 CS
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 2 of this data sheet.
© Semiconductor Components Industries, LLC, 2012
1
January, 2012 â Rev. 0
Publication Order Number:
NCP1253/D
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