adum1210 Analog Devices, Inc., adum1210 Datasheet - Page 15

• Manufacturer Part Number: adum1210
• Description: Dual-channel Digital Isolator
• Manufacturer: Analog Devices, Inc.

Note that, at combinations of strong magnetic fields and high
frequencies, any loops formed by printed circuit board traces
can induce sufficiently large error voltages to trigger the
threshold 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 ADuM1210
isolator is a function of the supply voltage, the channel data rate,
and the channel 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 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).
1000
I
I
I
I
0.01
is the output supply voltage (V).
DDI
DDI
DDO
DDO
100
, I
, I
0.1
10
1
DDO (D)
DDO (Q)
1k
= I
= I
= I
= (I
DISTANCE = 100mm
Figure 11. Maximum Allowable Current for Various
DDI (Q)
DDI (D)
DDO (Q)
DDO (D)
are the input and output dynamic supply currents
are the specified input and output quiescent
× (2f – f
DISTANCE = 5mm
10k
Current-to-ADuM1210 Spacings
+ (0.5 × 10
MAGNETIC FIELD FREQUENCY (Hz)
r
) + I
100k
DDI (Q)
−3
) × C
L
1M
V
DDO
DISTANCE = 1m
) × (2f – f
10M
r
) + I
f ≤ 0.5f
f > 0.5f
f ≤ 0.5f
f > 0.5f
100M
DDO (Q)
Rev. C | Page 15 of 20
r
r
r
r
To calculate the total I
currents for each input and output channel corresponding to
I
show per-channel supply currents as a function of data rate for
an unloaded output condition. Figure 6 shows per-channel
supply current as a function of data rate for a 15 pF output
condition. Figure 7 and Figure 8 show total V
supply current as a function of data rate.
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 ADuM1210.
Analog Devices performs accelerated life testing using voltage
levels higher than the rated continuous working voltage.
Acceleration 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 10
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 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 ADuM1210 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 12, Figure 13, and Figure 14 illustrate these
different isolation voltage waveforms.
Bipolar ac voltage is the most stringent environment. The goal
of a 50-year operating lifetime under the ac bipolar condition
determines the Analog Devices recommended maximum
working voltage.
DD1
and I
DD2
are calculated and totaled. Figure 4 and Figure 5
DD1
and I
DD2
supply current, the supply
DD1
ADuM1210
and V
DD2