Document 616 Toroidal Transformer – Q3903-AL • Specified by ON Semiconductor for use with their NCP1605 PFC Controller. Referenced as X25, pulse transformer on evaluation board NCP1605FORWGEVB and Application Note AND8292. • Recommended by Texas Instruments for use with their UC3875 Phase Shift Resonant Controller. • Three 1 : 1 windings • 500 Vrms winding-to-winding isolation. Core material Ferrite Terminations RoHS compliant tin-silver over tin over nickel over brass. Other terminations available at additional cost. Weight 4.3 g Ambient temperature –40°C to +85°C Storage temperature Component: –40°C to +85°C. Packaging: –40°C to +80°C Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C / 85% relative humidity) Failures in Time (FIT) / Mean Time Between Failures (MTBF) 38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332 Packaging 49 per tray PCB washing Only pure water or alcohol recommended Part number Inductance1 min (µH) DCR max2 (Ohms) Inter-winding isolation (Vrms) 1 6 Q3903-AL 210 0.090 500 2 5 3 4 1. Inductance measured between pins 1 and 6, at 15.75 kHz, 0.015 Vrms, 0 Adc using an Agilent/HP 4192A impedance analyzer. 2. DCR is per winding, measured on Cambridge Technology microohmmeter or equivalent. 3. Electrical specifications at 25°C. 1 Notch indicates pin1 0.65 16,51 6 2 0.72 18,29 0.95 24,13 5 3 4 0.475 12,07 1:1:1 0.19 ± 0.02 4,83 ± 0,51 0.01256 × 0.30 0,319 × 0,75 0.140 3,56 1 6 3 4 0.638 16,21 0.051 1,3 Recommended PC Board Layout Dimensions are in inches mm Specifications subject to change without notice. Please check our website for latest information. © Coilcraft, Inc. 2009 Document 616 Revised 05/27/09