NCP4302 Secondary Side Synchronous Flyback Controller The NCP4302 is a full featured controller and driver that provide all the control and protection functions necessary for implementing a www.onsemi.com synchronous rectifier operation in a flyback converter. With the use of the NCP4302, the space conscious flyback applications such as MARKING Adaptors, chargers, set top boxes can achieve significant efficiency DIAGRAM improvements at minimal extra cost. In addition to the synchronous 8 rectifier control, the IC incorporates an accurate TL431 type shunt 4302x SO8 regulator, current monitoring circuit and optocoupler driver to provide 8 ALYW D SUFFIX a single IC secondary solution. The NCP4302 works with any type of 1 CASE 751 flyback topology (continuous mode, Quasi resonant mode or 1 discontinuous mode) providing a high level of versatility. x = Reference Voltage (A or B) A = Assembly Location Features L = Wafer Lot Selfcontained Control of Synchronous Rectifier in CCM, DCM, and Y = Year QR Flyback Applications W = Work Week = PbFree Package Interface to External Signal for CCM Mode True Secondary Zero Current Detection High Gate Drive Currents (2.5 A Source/Sink) PIN CONFIGURATION High Voltage Operation Current Sense Flexibility (MOSFET R OR CS Resistor) SYNC/CS 1 8 V CC DS(on) Accurate Low Voltage Reference 2 7 TRIG DRV NCP4302A 2.55 V, 1% CATH 3 6 GND NCP4302B 1.275 V, 1% 4 Programmable Independent Secondary Side t and t Delays V 5 D on off REF LYADJ Maximum Frequency of Operation up to 250 kHz (Top View) These are PbFree Devices Typical Applications ORDERING INFORMATION Notebook Adapters LCD TV Adapters Device Package Shipping Consumer Appliances such as DVD, VCR NCP4302ADR2G SO8 2500/Tape & Reel Power Over Ethernet Applications (IP phones, Wireless Access (PbFree) Points) NCP4302BDR2G SO8 2500/Tape & Reel Battery Chargers (PbFree) For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: May, 2015 Rev. 4 NCP4302/DNCP4302 PIN DESCRIPTION Pin Number Symbol Description 1 SYNC/CS Connected to the flyback winding. The current on this pin is sensed and used to turn on the Synchronous Rectification MOSFET (SRFET). This pin is also used to sense the zero crossing of the MOSFET current either using the R of the SRFET or using an external current sense resistor connected between DS(on) drain of the SRFET and the flyback winding. 2 TRIG Input pin for direct turnoff of the MOSFET. Typically connected to a signal from primary controller (for CCM mode) or a signal derived from the transformer (for QR mode). Has very short propagation delay to output (<50 ns). 3 CATH Feedback compensation pin for the TL431 shunt regulator. Has the capability to sinking 10 ma of opto current. 4 V Output voltage feedback through resistive divider connected to this pin. Regulated at 1.28 V (option B) or REF 2.55 V (option A). 5 D A resistive divider between the power supply output and ground with the center point tied to the D LYADJ LYADJ input pin allows for independent adjustment of the minimum t and t delay time. The maximum extern- on off al capacitance from this pin to ground is 25 pF. 6 GND Return pin for the controller connected to the output return. 7 DRV Drive output for external MOSFET 2.5 A peak drive capability, internally clamped to 13.5 V (Maximum) 8 V Bias voltage for the controller. Maximum voltage is 28 V. CC MAXIMUM RATINGS Rating Symbol Value Unit Power Supply Input V 0.3 to 28 V CC Current I 100 mA CC Drive Voltage V 0.3 to 18 V DRV Current 100 mA Drive Current I Apk DRV Source 2.5 Sink 2.5 Analog and Logic Inputs TRIG, V , 0.3 to 10 V REF D 100 mA LYADJ Maximum Voltage SYNC/CS 10 to 95 V Current 100 mA Operating Junction Temperature Range T 40 to 125 C J Maximum Junction Temperature T 150 C Jmax Storage Temperature Range T 65 to 150 C Smax Lead Temperature (Soldering, 10 s) T 300 C Lmax Reference input Current, continuous I 0.05 to 10 mA REF Total Power Dissipation P 225 mW D Thermal Resistance JunctiontoAmbient 178 C/W JA Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. 1. This device series contains ESD protection and exceeds the following tests: Pin 18: Human Body Model 2000 V per JEDEC Standard JESD22, Method A114E. Machine Model (MM) 200 V per JEDEC Standard JESD22, Method A115A. 2. This device contains Latchup protection and exceeds 100 ma per JEDEC Standard JESD78 www.onsemi.com 2