ADUM1410 AD [Analog Devices], ADUM1410 Datasheet - Page 19

• Manufacturer Part Number: ADUM1410
• Description: Quad-Channel Digital Isolators
• Manufacturer: AD [Analog Devices]

For example, at a magnetic field frequency of 1 MHz, the
maximum allowable magnetic field of 0.2 kgauss induces a
voltage of 0.25 V at the receiving coil. This is about 50% of the
sensing threshold and does not cause a faulty output transition.
Similarly, if such an event occurs during a transmitted pulse
(and was of the worst-case polarity), it reduces the received
pulse from >1.0 V to 0.75 V—still well above the 0.5 V sensing
threshold of the decoder.
The preceding magnetic flux density values correspond to
specific current magnitudes at given distances from the
ADuM141x transformers. Figure 19 expresses these allowable
current magnitudes as a function of frequency for selected
distances. As shown, the ADuM141x is extremely immune and
can be affected only by extremely large currents operated at
high frequency very close to the component. For the 1 MHz
example noted, a 0.5 kA current needed to be placed 5 mm
away from the ADuM141x to affect the operation of the
component.
1000
0.01
100
0.1
10
1
1k
Figure 19. Maximum Allowable Current for Various
DISTANCE = 100mm
DISTANCE = 5mm
Current-to-ADuM141x Spacings
10k
MAGNETIC FIELD FREQUENCY (Hz)
100k
1M
DISTANCE = 1m
10M
100M
Rev. E | Page 19 of 20
Note that at combinations of strong magnetic field and high
frequency, any loops formed by printed circuit board traces
could induce error voltages sufficiently large enough to trigger
the thresholds of succeeding circuitry. Care should be taken in
the layout of such traces to avoid this possibility.
POWER CONSUMPTION
The supply current at a given channel of the ADuM141x
isolator is a function of the supply voltage, the data rate of the
channel, and the output load of the channel.
For each input channel, the supply current is given by
For each output channel, the supply current is given by
where:
I
per channel (mA/Mbps).
C
V
f is the input logic signal frequency (MHz); it is half of the input
data rate expressed in units of Mbps.
f
I
supply currents (mA).
To calculate the total V
currents for each input and output channel corresponding to
V
provide per-channel supply currents as a function of data rate
for an unloaded output condition. Figure 10 provides per-
channel supply current as a function of data rate for a 15 pF
output condition. Figure 11 through Figure 15 provide total
V
ADuM1410/ADuM1411/ADuM1412 channel configurations.
r
DDI (D)
DDI (Q)
L
DDO
is the input stage refresh rate (Mbps).
DD1
DD1
is the output load capacitance (pF).
I
I
I
I
and V
and V
is the output supply voltage (V).
DDI
DDI
DDO
DDO
, I
, I
DDO (D)
DDO (Q)
= I
= I
= (I
= I
ADuM1410/ADuM1411/ADuM1412
DD2
DD2
DDI (D)
DDI (Q)
DDO (Q)
DDO (D)
are the input and output dynamic supply currents
are the specified input and output quiescent
are calculated and totaled. Figure 8 and Figure 9
supply current as a function of data rate for
× (2f − f
+ (0.5 × 10
DD1
r
) + I
and V
−3
DDI (Q)
) × C
DD2
L
supply current, the supply
× V
DDO
) × (2f − f
r
f ≤ 0.5 f
f > 0.5 f
f ≤ 0.5 f
f > 0.5 f
) + I
DDO (Q)
r
r
r
r