NCP1254ASN65T1G ON Semiconductor

NCP1254 Product Preview Current-Mode PWM Controller for Off-line Power Supplies featuring Peak Power Excursion NCP1254 Vbulk Vout OVP OPP . NCP1254 1 6 2 5 3 4 ramp comp. Figure 1. Typical Application Schematic Table 1. PIN FUNCTION DESCRIPTION Pin No. Pin Name Function Description 1 GND The controller ground. 2 FB Feedback pin Hooking an optocoupler collector to this pin will allow regula- tion via peak current mode control or frequency modulation in highpower conditions. 3 OPP/OVP Adjust the Over Power Protection A resistive divider from the auxiliary winding to this pin sets the OPP compensation level. When brought above 3 V, the part is Latches off the part fully latched off. 4 CS Current sense + ramp compensation This pin monitors the primary peak current but also offers a means to introduce slope compensation. 5 V Supplies the controller protects the IC This pin is connected to an external auxiliary voltage. An OVP cc comparator monitors this pin and offers a means to latch the converter in fault conditions. 6 DRV Driver output The drivers output to an external MOSFET gate. Table 2. OPTIONS AND ORDERING INFORMATION Controller Frequency OCP Latched OCP Autorecovery NCP1254ASN65T1G 65 kHz Yes No NCP1254BSN65T1G 65 kHz No Yes