ADUM4401CRIZ Analog Devices Inc, ADUM4401CRIZ Datasheet - Page 16

• Manufacturer Part Number: ADUM4401CRIZ
• Description: 63T8644
• Manufacturer: Analog Devices Inc

Specifications of ADUM4401CRIZ

• No. Of Channels: 4
• Propagation Delay: 32ns
• Supply Current: 59mA
• Supply Voltage Range: 2.7V To 5.5V
• Digital Ic Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +105°C

ADuM4400/ADuM4401/ADuM4402
The pulses at the transformer output have an amplitude greater
than 1.0 V. The decoder has a sensing threshold at about 0.5 V,
thereby establishing a 0.5 V margin in which induced voltages
can be tolerated. The voltage induced across the receiving coil is
given by
where:
β is the magnetic flux density (gauss).
N is the number of turns in the receiving coil.
r
Given the geometry of the receiving coil in the ADuM440x and
an imposed requirement that the induced voltage be at most
50% of the 0.5 V margin at the decoder, a maximum allowable
magnetic field is calculated as shown in Figure 19.
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 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
ADuM440x transformers. Figure 20 expresses these allowable
current magnitudes as a function of frequency for selected
distances. As can be seen, the ADuM440x are 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 ADuM440x to affect the component’s operation.
n
is the radius of the n
V = (−dβ/dt)Σ∏r
0.001
Figure 19. Maximum Allowable External Magnetic Flux Density
0.01
100
0.1
10
1
1k
10k
MAGNETIC FIELD FREQUENCY (Hz)
n
2
th
; n = 1, 2,…, N
turn in the receiving coil (cm).
100k
1M
10M
100M
Rev. 0 | Page 16 of 20
Note that at combinations of strong magnetic field and high
frequency, any loops formed by printed circuit board traces may
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 ADuM440x
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
supply currents (mA).
r
DDI (D)
DDI (Q)
L
DDO
is the input stage refresh rate (Mbps).
is the output load capacitance (pF).
I
I
I
I
is the output supply voltage (V).
1000
DDI
DDI
DDO
DDO
, I
, I
0.01
100
0.1
10
DDO (D)
DDO (Q)
1
= I
= I
1k
= I
= (I
DISTANCE = 100mm
DDI (Q)
DDI (D)
DDO (Q)
DDO (D)
are the input and output dynamic supply currents
are the specified input and output quiescent
for Various Current-to-ADuM440x Spacings
Figure 20. Maximum Allowable Current
× (2f − f
DISTANCE = 5mm
+ (0.5 × 10
10k
MAGNETIC FIELD FREQUENCY (Hz)
r
) + I
100k
−3
DDI (Q)
) × C
L
1M
V
DDO
DISTANCE = 1m
) × (2f − f
10M
r
) + I
100M
DDO (Q)
f ≤ 0.5f
f > 0.5f
f ≤ 0.5f
f > 0.5f
r
r
r
r