NCP1205 Datasheet (ON Semiconductor) - Single Ended PWM Controller

NCP1205, Single Ended PWM Controller

Pin No.

PDIP *8 PDIP *14 SOIC *16 Pin Name 1 1 1 HV Function Startup rail 2 3 3 4 4 5 4 Demag Zero primary *current detection 5 FB Feedback signal to control the PWM 6 Ct Timing capacitor 5 10 11 GND The IC’s ground NA 6 7 OVP Overvoltage

NCP1205 Single Ended PWM Controller Featuring QR Operation and Soft Frequency Foldback The NCP1205 combines a true Current Mode Control modulator and a demagnetization detector to ensure full Discontinuous Conduction Mode in any load/line conditions and minimum drain voltage switching (Quasi Resonant operation, also called critical conduction operation).

With its inherent Variable Frequency Mode (VFM), the controller decreases its operating frequency at constant peak current whenever th

NCP1205 Features

* Natural Drain Valley Switching for Lower EMI and Quasi

* Resonant Operation (QR)

* Smooth Frequency Foldback for Low Standby and Minimum Ripple at Light

* Load

* Adjustable Maximum Switching Frequency

* Internal 200 ns Leading Edge Blanking on Current Sense

* 250 mA