Onsemi NCP1365 | Demoboard DN05074/D

Description

The NCP1360/65 offers a new solution targeting output powerlevels from a few watts up to 20 W in a universal−mains flyback application. Thanks to a novel method this new controller saves the secondary feedback circuitry (opto−coupler and TL431 reference) while achieving excellent line and load regulation.The NCP1360/65 operates in valley−lockout quasi−resonant peak current mode control mode at nominal load to provide high efficiency.When the secondary−side power starts diminishing, the switching frequency naturally increases until a voltage−controlled oscillator (VCO) takes the lead, synchronizing the MOSFET turn−on in a drain−source voltage valley. The frequency is thus reduced by stepping into successive valleys until the number 4 is reached. Beyondthis point, the frequency is linearly decreased in valley−switching mode until a minimum is hit. This technique keeps the output in regulation with the tiniest dummy load. Valley lockout during the first four drain−source valleys prevents erratic discrete jumps and provides good efficiency in lighter load situations.

Features

• Primary−Side Feedback Eliminates Opto−coupler and TL431Reference
• ±5% Voltage Regulation
• ±10% Current Regulation
• 560 V Startup Current Source
• No Frequency Clamp, 80 or 110 kHz MaximumSwitching Frequency Options
• Quasi−Resonant Operation with Valley SwitchingOperation
• Fixed Peak Current & Deep Frequency Foldback @Light Load Operation.
• External Constant Voltage Feedback Adjustment
• Cycle by Cycle Peak Current Limit
• Build−In Soft−Start
• Over & Under Output Voltage Protection
• Cable Drop Compensation (None, 150 mV, 300 mV or450 mV option)
• Wide Operation VCC Range (up to 28 V)Low Start−up Current (2.5 A typ.) with NCP1360
• Clamped Gate−drive Output for MOSFET
• CS & Vs/ZCD pin Short and Open Protection
• Internal Temperature Shutdown
• Less than 10 mW No−Load Performance at High Linewith NCP1365 Version
• Less than 30 mW No−Load Performance at High Linewith NCP1360 Version
• These are Pb−Free Devices

Typical applications

• Ac−dc USB chargers for Cell Phones, Tablets and Cameras
• Low power ac−dc Adapters for Chargers.

More information

• Datasheet