FAN302UL Datasheet, PDF (17/19 Pages) Fairchild Semiconductor – PWM Controller for Low Standby Power Battery-Charger Applications

Typical Application Circuit (Continued)
Transformer Specification
 Core: EI12.5
 Bobbin: EI12.5
Figure 44.Transformer
 W1 is space winding in one layer.
 W2 consists of three layers with different numbers of turns. The number of turns of each layer is specified in
Table 1.
 W3 consists of two layers with triple-insulated wire. The leads of positive and negative fly lines are 3.5cm and
2.5cm, respectively.
Table 1. Transformer Winding Specifications
Terminal
No.
Start Pin
End Pin
W1
1
2
W2
4
5
W3
Fly+
Fly-
Wire
2UEW 0.15*2
2UEW 0.12*1
TEX-E 0.4*1
Turns
8
22
22
22
5
Insulation
Turns
2
0
1
3
3
Primary-Side Inductance
Primary-Side Effective Leakage Inductance
Pin
4－5
4－5
Specifications
Remark
530μH ±7% 100kHz, 1V
52μH ±5%
Short One of the Secondary Windings
© 2011 Fairchild Semiconductor Corporation
FAN302UL • Rev. 1.0.3
17
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