Current-Mode Controller, Fixed Frequency, for Two-Switch Forward Converter NCL30125 www.onsemi.com The NCL30125 is a fixedfrequency currentmode controller featuring the Dynamic SelfSupply (DSS). This function greatly simplifies the design of the auxiliary supply and the V capacitor by cc activating the internal startup current source to supply the controller during startup, transients, latch, standby etc. With a supply range up to 35 V, the controller hosts an adjustable SOIC16 switching frequency with jittering function operated in peak current CASE 751DU mode control. When the power on the secondary side drops drastically, the part enters skip cycle while limiting the peak current that insures the output voltage regulation and excellent efficiency in light load MARKING DIAGRAM condition. 16 It features a timerbased fault detection that ensures the detection of XXXXXXXXXX overload and a brown out protection against low input voltages. AWLYWWG Features 1 Integrated Highside Driver XXXXX = Specific Device Code Adjustable Switching Frequency Up to 300 kHz A = Assembly Location Peak Currentmode Control WL = Wafer Lot Y = Year Skip Mode to Maximize Performance in Light Load Conditions WW = Work Week Highvoltage Current Source with DSS G = PbFree Package Brownout (BO) Detection Internal Slope Compensation PIN CONNECTION Adjustable Softstart Duration Frequency Jittering 11HV Boot6 15 ms Timerbased Shortcircuit Protection with Autorecovery or Latched Operation 2 HB 15 Autorecovery or Latched OVP on V cc Latched OVP/OTP Input for Improved Robustness Fault DRV HI 3 14 35V V Operation cc 4 BO 13 +0.9 A / 1.2 A Peak Source/Sink Drive Capability Internal Thermal Shutdown 5 FB DRV LO 12 These Devices are PbFree and are RoHS Compliant 6 RT GND 11 Typical Applications Power Supplies for PC Silver Boxes, Games Adapter 71SS Vcc0 TwoSwitch Forward Converter DctoDc Application Capability 8 FW CS 9 ORDERING INFORMATION See detailed ordering, marking and shipping information in the package dimensions section on page 34 of this data sheet. Semiconductor Components Industries, LLC, 2018 1 Publication Order Number: January, 2020 Rev. 0 NCL30125/DNCL30125 Figure 1. TwoSwitch Forward Application Schematic Vcc hiccup Latch Autorecovery HV Boot Thermal TSD Startup Shutdown UVLO Reset UVLO Detect V dd Vcc Management Start-up Logic Reset DRV HI POReset Vcc Drivers HB Vcc hiccup Latch Autorecovery DRV LO RT Clock Logic Jittering Main Logic Up to 1 MHz Clamp FW Signal GND LEB1 LEB2 Ramp MaxDC Fault Logic OVP/OTP Fault OVP/OTP FW Skip mode Skip Logic FB LineOVP FB Reset BO and LineOVP Logic BO Current Limiation BO NOK And Regulation Loop Max Ipk reset CS TSD OCP SCP Vcc Hiccup OVP/OTP Autorecovery, Latch or Soft Start Ramp LineOVP Vcc hiccup Logic Autorecovery SS generation BO NOK UVLO Reset Latch CS pin Fault Vcc(OVP) Reset POReset Figure 2. Simplified Block Diagram www.onsemi.com 2