adum5200 Analog Devices, Inc., adum5200 Datasheet - Page 20

• Manufacturer Part Number: adum5200
• Description: Dual-channel Isolators With Integrated Dc/dc Converter
• Manufacturer: Analog Devices, Inc.

ADuM5200/5201/5202
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 V
data channels as well as the power converter. For this reason,
the quiescent currents drawn by the data converter and the
primary and secondary I/O channels cannot be determined
separately. All of these quiescent power demands have been
combined into the I
total I
operating current, dynamic current I
channels, and any external I
Both Dynamic I/O current is consumed only when operating at
channel at speeds higher than the rate f
have a dynamic current that is determined by its data rate,
Figure 15 shows the current for a channel in the forward
direction, which means that the input on the primary side of the
part. Figure 16 shows the current for a channel in the reverse
1000
0.01
DD1
100
DD1
0.1
10
1
1k
supply current will be the sum of the quiescent
power supply input provides power to the iCoupler
Figure 21 Power consumption within the ADuM520x
DISTANCE = 100mm
for Various Current-to-ADuM520x Spacings
Figure 20. Maximum Allowable Current
DISTANCE = 5mm
10k
DD1(Q)
MAGNETIC FIELD FREQUENCY (Hz)
current as shown in Figure 21. The
100k
ISO
load.
DD1(D)
1M
r
. Since each channel will
DISTANCE = 1m
demanded by the I/O
10M
100M
Rev. PrA | Page 20 of 23
direction, which means that the input on the secondary side of
the part. Both figures assume a typical 15pF load. The
following relationship allows the total I
calculated.
Where :
The maximum external load can be calculated by subtracting
the dynamic output load from the maximum allowable load.
Where:
The preceding analysis assumes a 15pF capacitive load on each
data output. If a capacitive load larger than 15pF, he additional
current must be included in the analysis of I
To determine I
dynamic output current I
Additional secondary side dynamic output current I
to I
To determine I
output current I
basis.
For each output channel with C
additional capacitive supply current is given by:
Where:
I
I
Figure 15 or Figure 16 depending on channel direction.
I
E is the power supply efficiency at 100mA load from Figure 6
at the V
I
secondary side load.
I
available at V
I
input or output channel, as shown in Figure 15 and Figure 16.
Data is presented assuming a typical 15pF load
C
V
f is the input logic signal frequency (MHz); it is half of the
input data rate expressed in units of Mbps.
f
r
DD1
CHn
ISO
ISO(LOAD)
ISO(MAX)
ISO(D)n
ISO
L
ISO
is the input channel refresh rate (Mbps).
is the output load capacitance. (pF).
is the current drawn by the secondary side external loads.
on a per channel basis.
is the total supply input current.
is the current drawn by a single channel determined from
is the output supply voltage (V).
is the dynamic load current drawn from V
ISO
is the maximum external secondary side load current
I
AOD
is the current available to supply an external
and V
= 0.5 × 10
I
DD1
DD1
ISO(LOAD)
ISO
AOD
= (I
I
ISO(LOAD)
.
in Equation 1, additional primary side
DD1
is subtracted from I
ISO
−3
Preliminary Technical Data
× V
condition of interest.
in Equation 2, additional secondary side
× (C
= I
ISO
AOD
ISO(MAX)
)/(E × V
L
Equation 1
Equation 2
Equation 3
-15) × V
is added directly to I
- ∑ I
L
DD1
greater than 15pF, the
ISO
ISO(D)n
) + ∑ I
) × (2f − f
; n = 1to 4
DD1
ISO(MAX)
CHn
; n = 1to 4
current to be
r
)
DD1
on a per channel
and I
f > 0.5 f
DD1
ISO
AOD
.
ISO(LOAD)
r
by an
is added
.