Datasheet

W
= V
(
BR
)
L
R
[ I
o
−
V
(
BR
)
− V
CC
R
Log ( 1 +
V
CC
V
(
BR
)
− V
CC
) ]
SHORT CIRCUIT CONDITIONS WITH CONTROLLED RESET
DEMAGNETIZATION OF INDUCTIVE LOADS
WITHOUT EXTERNAL CLAMPING DEVICES.
With no external clamping device, the energy of
demagnetization is dissipated in the TDE1798
output stage, and the clamping voltage is the col-
lector -emitter breakdown voltage V
(BR)CEO
.
This method provides a very fast demagnetization
of inductive loads and can be used up to 150 mJ.
The amount of energy W dissipated in the output
stage during a demagnetization is :
Remark 1 : This energy is dissipated inside the
case, then must be included in the whole power
dissipation.
Remark 2 : The use of external clamping device
is recommended in case of parallel driving of
loads. The dispersion of the collector-emitter
breakdown voltage V(BR) would induce the circuit
with the lowest V(BR) to dissipate the whole de-
magnetization energy (which is roughly propor-
tionnal to I
O
2
).
TDE1798
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