5 08/15
Please read Cautions and warnings and
Important notes at the end of this document.
With:
B
max
Maximum magnetic flux density in the ferrite core of the current sense transformer
V
sense,max
Maximum output voltage of the measurement signal
max
Maximum duty cycle
n
s
Number of turns of the secondary winding of the current sense transformer
A
e
Effective magnetic area of the ferrite core
f
osc
Operating frequency of the switching operator IC
Typical value for A
e
: 2.5 x 10
-6
m
2
Typical B
max
: 200 mT
With:
R
T
Resistance of burden resistor
V
sense,max
Maximum output voltage of the measurement signal
n
s
Number of turns on the secondary side of the CT
I
prim,max
Maximum primary current (peak current)
Characteristics and ordering codes
L
min
H
Turns ratio
N
p
: N
s
DC resistance
R
max
(m)
Voltage-
time product
V µs
Recomm.
R
T
Ordering code
primary secondary
80 1 : 20 0.6 400 10.0 20 B82801B0803A020
180 1 : 30 0.6 870 15.0 30 B82801B0184A030
320 1 : 40 0.6 1140 20.0 40 B82801B0324A040
500 1 : 50 0.6 1500 25.0 50 B82801B0504A050
720 1 : 60 0.6 1980 30.0 60 B82801B0724A060
980 1 : 70 0.6 3000 35.0 70 B82801B0984A070
2000 1 : 100 0.6 5500 50.0 100 B82801B0205A100
3000 1 : 125 0.6 6500 62.5 125 B82801B0305A125
8000 1 : 200 0.6 33240 100.0 200 B82801B0925A200
B
max
V
sense max
max
n
s
A
e
f
osc
-----------------------------------------
=
R
T
V
sense max
n
s
I
prim max
-----------------------------------
=
B82801B
EE 5.0
SMT current sense transformers
