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NCP1253BSN65T1G 全新进口原装，欢迎来电咨询洽谈订购！ 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 VCC 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 VCC
• Up to 28 V VCC 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 
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