ADuM5210ARSZ datasheet(21/24 Pages) AD

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Data Sheet

ADuM5210/ADuM5211/ADuM5212

Rev. 0 | Page 21 of 24

The preceding magnetic flux density values correspond to specific

current magnitudes at given distances from the ADuM5210/

ADuM5211/ADuM5212 transformers. Figure 29 expresses these

allowable current magnitudes as a function of frequency for

selected distances. As shown in Figure 29, the ADuM5210/

ADuM5211/ADuM5212 are 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,

a 0.5 kA current, placed 5 mm away from the ADuM5210/

ADuM5211/ADuM5212, is required to affect component

operation.

MAGNETIC FIELD FREQUENCY (Hz)

100

0.1

0.01

10k

100M

100k

10M

DISTANCE = 5mm

DISTANCE = 1m

DISTANCE = 100mm

Figure 29. Maximum Allowable Current for Various Current-to-ADuM521x

Spacings

Note that, in combinations of strong magnetic field and high

frequency, any loops formed by PCB traces can induce error

voltages sufficiently large to trigger the thresholds of succeeding

circuitry. Exercise care in the layout of such traces to avoid this

possibility.

POWER CONSUMPTION

The VDDP power supply input provides power only to the converter.

Power for the data channels is provided through VDD1 and VDD2.

These power supplies can be connected to VDDP and VISO, if desired,

or the supplies can receive power from an independent source. The

converter should be treated as a standalone supply to be utilized at

the discretion of the designer.

The VDD1 or VDD2 supply current at a given channel of the

ADuM5210/ADuM5211/ADuM5212 isolator is a function of

the supply voltage, the data rate of the channel, and the output

load of the channel.

For each input channel, the supply current is given by

IDDI = IDDI(Q)

f ≤ 0.5 fr

IDDI = IDDI(D) × (2f − fr) + IDDI(Q)

f > 0.5 fr

For each output channel, the supply current is given by

IDDO = IDDO(Q)

f ≤ 0.5 fr

IDDO = (IDDO(D) + (0.5 × 10−3) × CL × VDDO) × (2f − fr) + IDDOQ)

f > 0.5 fr

where:

IDDI(D), IDDO(D) are the input and output dynamic supply currents

per channel (mA/Mbps).

IDDI(Q), IDDO(Q) are the specified input and output quiescent

supply currents (mA).

f is the input logic signal frequency (MHz); it is half the input

data rate, expressed in units of Mbps.

fr is the input stage refresh rate (Mbps).

CL is the output load capacitance (pF).

VDDO is the output supply voltage (V).

To calculate the total VDD1 and VDD2 supply current, the supply

currents for each input and output channel corresponding to

VDD1 and VDD2 are calculated and totaled. Figure 18 and

Figure 19 show per-channel supply currents as a function of

data rate for an unloaded output condition. Figure 20 shows the

per-channel supply current as a function of data rate for a 15 pF

output condition. Figure 21 through Figure 23 show the total

VDD1 and VDD2 supply current as a function of data rate for

ADuM5210/ ADuM5211/ADuM5212 channel configurations.

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