IXBD4410
IXBD4411
The nominal electrical specifications of
the transformer are as follows:
Open circuit inductance
(100 kHz; 20 mV):
3
µH
Interwinding capacitance:
2 pF
Primary leakage inductance: 0.1
µH
Turns ratio:
6:2
Primary-to-secondary isolation
(1min):
1500 V~
Core permeability (µ
i
):
125
The recommended ferrite bead is Fair
Rite Products part number 2661000101,
which is manufactured by:
Fair-Rite Products Corp.
Wallkill, NY
Phone: (800) 836-0427
Web site: www.fair-rite.com
As seen in the application drawings
(Fig. 6, 9 and 12) a coupling capacitor
(22 nF) and a damping resistor (22
Ω)
are added in series with the primary
side of the transformer. The capacitor
will control the small amount of energy
needed to transfer the signal to the
companion driver. The resistor will
control the damping of the signal and
limit the peak transmitter output current.
The receiver is designed to operate
Fig. 11: Ferrite bead dimensions
over a wide common mode input range.
To reduce noise pickup, the receiver
has
±250
mV of input hysteresis.
If the signal is being distorted at the
transmitter, the transmitter is probably
running into current limit. A decrease in
the coupling capacitance or an increase
in the damping resistance should solve
this problem. The receiver operates
over a wide input range. The minimum
amplitude for one side of the receiver is
about 1 V and a maximum of about 3 V.
It is critical that there be no overshoot
on the transformer secondary wave-
form. Each signal should be slightly
overdamped. If significant overshoot
exists, the received signal may be
logically inverted. An increase of the
damping resistor will solve this problem.
Fig. 12: Transmitter/Receiver Waveforms
DS96528E(05/04)
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11
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