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The NCP1256 includes everything to build cost−effective switch

mode power supplies ranging from a few watts up to several tens of

watts. Housed in a tiny TSOP−6 package, the part can be supplied up

to 30 V. It hosts a jittered 65 or 100−kHz switching circuitry operated

in peak current mode control. When the power in the secondary side

starts decreasing, 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 freezing the peak current.

NCP1256 comes with several protection features such as a

timer−based auto−recovery short circuit protection, lossless OPP, and

an easily adjustable Brown Out (BO) pin. Two inputs are provided to

latch off the part in a practical way, for instance with OVP and OTP

events. Several options exists to chose latch or auto−recovery for these events.

特性 Features

• Fixed−frequency 65−kHz or 100−kHz Current−mode Control

Operation

• Adjustable Over Power Protection (OPP) Circuit, Disabled at Low

Line

• Adjustable Brown Out Level

• Frequency Foldback down to 26 kHz and Skip−cycle in Light Load

Conditions

• Internally−fixed Slope Compensation Ramp

• Internally−fixed 4−ms Soft−start

• 70−ms Timer−based Auto−recovery Short−circuit Protection

• Frequency Jittering in Normal and Frequency Foldback Modes

• Double Hiccup Auto−recovery Short−circuit Protection

• Pre−short Ready for Latched OCP Option

• Latched/Auto−Recovery OVP Protection on Vcc

• Latched Inputs for Improved Robustness (OVP and OTP

implementations)

• Auto−Recovery ac Line OVP Protection (E Version)

• +500 mA/ −500 mA Source/Sink Drive Capability

• EPS 2.0 Compliant

• These are Pb−Free Devices

Typical Applications

• Ac−dc Adapters for Portable Devices, Computers, Tablets etc.

• Auxiliary Power Supplies