Diodes AP3981B, User Manual, Page: 2 / 12

Universal AC input, Primary Side Regulation
AP3981B 12V-500mA EV2 Board User Guide
AP3981B EV2 Page 2 of 12 11 - 12 - 2019
Rev1.0 www.diodes.com
AP3981B (90 V
AC
~ 265V
AC
one outputs 10W Transformer Spec.)
1) C o r e & Bobbin: EE16C , 5+2 pin 2) Electrical Diagram:
3) Transformer Parameters
1. Primary Inductance (Pin3-Pin5), all other windings are open Lp =1.75mH ± 7 % @1KHz
EE16C （
Ae = 19mm^2
）
NO
Winding
NAME
TERMINAL NO. WINDING
START FINISH WIRE TURNS Layers
1 Shield 4
（
GND
）
NC
Φ 0.16mm x 3
15Ts 1
2 Np1 3 5
Φ 0.16mm x1
130 Ts 3
3 Na 1 4
Φ 0.16mm x 2
22T 1
4 Ns 9
6
Φ 0.25W x 1
18Ts 1
Primary Inductance Pin 3-5,all other windings
open, measured at 1kHz,
0.4VRMS 1.75mH ± 7 %
Primary Leakage
Inductance Pin 3-5, all other windings
shorted, measured at 10kHz,
0.4VRMS 80 uH (Max.)