ADUM3160BRWZ-RL Analog Devices Inc, ADUM3160BRWZ-RL Datasheet - Page 12

• Manufacturer Part Number: ADUM3160BRWZ-RL
• Description: 2.5kVFull/Low Speed USB Digital Isolator
• Manufacturer: Analog Devices Inc
• Series: iCoupler®r

Specifications of ADUM3160BRWZ-RL

• Operating Temperature: -40°C ~ 105°C
• Inputs - Side 1/side 2: 2/2
• Number Of Channels: 4
• Isolation Rating: 2500Vrms
• Voltage - Supply: 3 V ~ 5.5 V
• Data Rate: 12Mbps
• Propagation Delay: 70ns
• Output Type: Logic
• Package / Case: 16-SOIC (0.300", 7.50mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADuM3160
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, thus
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 magnetic flux density (gauss).
N is the number of turns in the receiving coil.
r
Given the geometry of the receiving coil in the ADuM3160 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 6.
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 from the
ADuM3160 transformers. Figure 7 expresses these allowable
current magnitudes as a function of frequency for selected
distances. As shown, the ADuM3160 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 must be placed 5 mm away
from the ADuM3160 to affect component operation.
n
is the radius of the n
V = (−dβ/dt)
0.001
0.01
Figure 6. Maximum Allowable External Magnetic Flux Density
100
0.1
10
1
1k
∑
10k
∏r
MAGNETIC FIELD FREQUENCY (Hz)
n
th
2
; n = 1, 2, … , N
turn in the receiving coil (cm).
100k
1M
10M
100M
Rev. A | Page 12 of 16
Note that, at combinations of strong magnetic field and high
frequency, any loops formed by printed circuit board traces may
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.
INSULATION LIFETIME
All insulation structures eventually break down when subjected
to voltage stress over a sufficiently long period. The rate of
insulation degradation is dependent on the characteristics of the
voltage waveform applied across the insulation. In addition to
the testing performed by the regulatory agencies, Analog Devices
carries out an extensive set of evaluations to determine the
lifetime of the insulation structure within the ADuM3160.
Analog Devices performs accelerated life testing using voltage
levels higher than the rated continuous working voltage. Accel-
eration factors for several operating conditions are determined.
These factors allow calculation of the time to failure at the
actual working voltage. The values shown in Table 8 summarize
the peak voltage for 50 years of service life for a bipolar ac
operating condition and the maximum CSA/VDE approved
working voltages. In many cases, the approved working voltage
is higher than the 50-year service life voltage. Operation at these
high working voltages can lead to shortened insulation life in
some cases.
The insulation lifetime of the ADuM3160 depends on the
voltage waveform type imposed across the isolation barrier.
The iCoupler insulation structure degrades at different rates
depending on whether the waveform is bipolar ac, unipolar ac,
or dc. Figure 8, Figure 9, and Figure 10 illustrate these different
isolation voltage waveforms.
1000
0.01
100
0.1
10
1
1k
DISTANCE = 100mm
for Various Current-to-ADuM3160 Spacings
Figure 7. Maximum Allowable Current
10k
DISTANCE = 5mm
MAGNETIC FIELD FREQUENCY (Hz)
100k
1M
DISTANCE = 1m
10M
100M