Low Power Offline PWM Current Mode Controller with Brown-Out Protection

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 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. 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.