UM10412
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© NXP B.V. 2010. All rights reserved.
User manual
Rev. 1 — 2 November 2010
14 of 26
NXP Semiconductors
UM10412
UBA2021 evaluation board
6. Transformer
specifications
6.1 Transformer
T1
6.1.1 Schematic diagram
•
Manufacturer: Würth Elektronik
•
Part number: 760870401
6.1.2 Winding specification
6.1.3 Dimensions
•
Core: RM-8 (Ferroxcube RM/I or equivalent)
•
Core material: 3F3, N87 or equivalent
•
Bobbin: RM-8 (12 pin, vertical type)
Fig 10. Transformer T1 schematic diagram
019aaa301
N3
10
12
7
9
6
1
N2
N1
Table 13.
Electrical characteristics for transformer T1
Properties
Test conditions
Value
Unit
Tolerance
Inductance N1
50 kHz/0.1 V
L
0
2.9
mH
±
5
%
Turns ratio N1 - N5
N1: N2: N3
TR
26.1 : 1 : 1
±
3
%
DC-resistance N1
at 20 °C
R
DC1
2.7
Ω
maximum
DC-resistance N2
at 20 °C
R
DC2
180
m
Ω
maximum
DC-resistance N3
at 20 °C
R
DC3
180
m
Ω
maximum
Saturation current N1
dL/L=20 %
I
SAT
1.6
A
typical
Leakage inductance N1
200 kHz/0.1 V rest shorted L
S
350
μ
H
maximum
Coupling capacitance
20 kHz/1 V all windings
C
WW
11.0
pF
typical
Hipot test
3 mA, 1s all windings
HV
1.2
kV