ADUM2401 AD [Analog Devices], ADUM2401 Datasheet - Page 20

• Manufacturer Part Number: ADUM2401
• Description: Quad-Channel Digital Isolators, 5KV
• Manufacturer: AD [Analog Devices]

ADuM2400/ADuM2401/ADuM2402
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 will not cause a faulty output transition.
Similarly, if such an event were to occur during a transmitted
pulse (and was of the worst case polarity) it would reduce 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 away from the ADuM240x
transformers.
magnitudes as a function of frequency for selected distances. As can
be seen, the ADuM240x is extremely immune and can be affected
only by extremely large currents operated at high frequency and very
close to the component. For the 1 MHz example noted, one would
have to place a 0.5 kA current 5 mm away from the ADuM240x to
affect the component’s operation.
0.001
0.01
100
Figure 19. Maximum Allowable External Magnetic Flux Density
0.1
10
1000
1
0.01
100
1k
0.1
10
1
1k
DISTANCE = 100mm
Figure 20
for Various Current-to-ADuM240x Spacings
Figure 20. Maximum Allowable Current
10k
DISTANCE = 5mm
MAGNETIC FIELD FREQUENCY (Hz)
10k
MAGNETIC FIELD FREQUENCY (Hz)
expresses these allowable current
100k
100k
1M
1M
DISTANCE = 1m
10M
10M
100M
100M
Rev. PrD| Page 20 of 23
Note that at combinations of strong magnetic field and high
frequency, any loops formed by printed circuit board traces
could induce sufficiently large error voltages 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 ADuM240x
isolator is a function of the supply voltage, the channel’s data
rate, and the channel’s output load.
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, half of the input data
rate, NRZ signaling).
f
I
currents (mA).
To calculate the total I
currents for each input and output channel corresponding to
I
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 14 provide total I
and I
ADuM2400/ADuM2401/ADuM2402 channel configurations.
r
DDI(D)
DDI(Q)
DD1
L
DDO
is the input stage refresh rate (Mbps).
is output load capacitance (pF).
I
I
I
I
and I
DDI
DDI
DDO
DDO
DD2
, I
is the output supply voltage (V).
, I
DDO(D)
DDO(Q)
= I
= I
= I
= (I
supply current as a function of data rate for
DD2
DDI(Q)
DDI(D)
DDO(Q)
DDO(D)
are calculated and totaled. Figure 8 and Figure 9
are the input and output dynamic supply currents
are the specified input and output quiescent supply
× (2f – f
+ (0.5 x 10
Preliminary Technical Data
DD1
r
) + I
and I
-3
DDI(Q)
× C
DD2
L
supply current, the supply
V
DDO
) × (2f – f
r
) + I
DDO(Q)
f ≤ 0.5f
f > 0.5f
f ≤ 0.5f
f > 0.5f
DD1
r
r
r
r