Product Overview NCP1239: Fixed Frequency Current Mode Controller for Flyback Converter with HV startup For complete documentation, see the data sheet Product Description The NCP1239 is a fixed-frequency current-mode controller featuring the Dynamic Self-Supply. This function greatly simplifies the design of the auxiliary supply and the Vcc capacitor by activating the internal startup current source to supply the controller during start-up, transients, latch, stand-by etc. With a supply range up to 35 V, the controller hosts a jittered 65 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 minimum level of 26 kHz. As the power further goes down, the part enters skip cycle while limiting the peak current that insures excellent efficiency in light load condition. It features a timer-based fault detection that ensures the detection of overload and an adjustable compensation to help keep the maximum power independent of the input voltage. Features Benefits • Fixed-frequency 65-kHz or 100-kHz current-mode control operation • Frequency foldback down to 26 kHz and skip mode • Adjustable Over Power Protection (OPP) circuit • High-voltage Current Source with Brown-out (BO) detection • Internal fixed 8-ms soft-start • Frequency jittering in normal and frequency foldback modes • 64-ms timer-based short-circuit protection with auto-recovery or latched operation • Pre-short ready • Latched OVP on Vcc (NCP1239 A & B versions) • Latched OVP/OTP input for improved robustness For more features, see the data sheet • Fixed-frequency is simple to implement and predictable in term of EMI • Maximize performance in light load conditions • OPP can be adjusted to the need of specific applications • BO monitor and detect a falling input voltage, needed in some applications • Simplified implementation that does not require programming • Lowers switching frequency EMI • Allows for safe operation while tolerant to faults if needed • Safe operation yet tolerant to faults • Safe operation • Safe operation Applications • Ac-dc converters for TVs, set-top boxes and printers • Offline adapters for notebooks and netbooks Part Electrical Specifications Product Compliance Status Topolog y Control Mode fsw Typ (kHz) StandUVLO by Mode (V) Short Circuit Protecti on Latch Soft Start VCC Max Drive (V) Cap. (mA) Packag e Type NCP1239AD100R2G Pb-free NEW Flyback Current Mode 100 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 NEW Flyback Current Mode 65 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 NEW Flyback Current Mode 100 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 NEW Flyback Current Mode 65 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 NEW Flyback Current Mode 65 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 NEW Flyback Current Mode 65 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 NEW Flyback Current Mode 65 Yes 8 Yes Yes Yes 35 500 / 500 SOIC-7 Halide free NCP1239AD65R2G Pb-free Halide free NCP1239BD100R2G Pb-free Halide free NCP1239BD65R2G Pb-free Halide free NCP1239CD65R2G Pb-free Halide free NCP1239DD65R2G Pb-free Halide free NCP1239ED65R2G Pb-free Halide free For more information please contact your local sales support at www.onsemi.com Created on: 6/30/2016