Data Sheet

ADuM5010

Rev. A | Page 13 of 16

THERMAL ANALYSIS

The ADuM5010 consist of two internal die attached to a split lead

frame with two die attach paddles. For the purposes of thermal

analysis, the chip is treated as a thermal unit, with the highest

on a JEDEC standard, 4-layer board with fine width traces and

still air. Under normal operating conditions, the ADuM5010

can operate at full load across the full temperature range without

derating the output current.

Power dissipation in the part varies with ambient temperature

due to the characteristics of the switching and rectification

elements. Figure 14 and Figure 15 show the relationship

between total power dissipation at two load conditions

and ambient temperature. This information can be used

to determine the junction temperature at various operating

conditions to ensure that the part does not go into thermal

shutdown unexpectedly.

EMI CONSIDERATIONS

The dc-to-dc converter section of the ADuM5010 components

must, of necessity, operate at a very high frequency to allow

efficient power transfer through the small transformers.

This creates high frequency currents that can propagate in

circuit board ground and power planes, causing edge and

dipole radiation. Grounded enclosures are recommended for

applications that use these devices. If grounded enclosures are not

possible, follow good RF design practices in the layout of the

PCB. See the AN-0971 Application Note at www.analog.com for

the most current PCB layout recommendations for the ADuM5010.

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. Analog Devices conducts

an extensive set of evaluations to determine the lifetime of the

insulation structure within the ADuM5010.

Accelerated life testing is performed using voltage levels higher

than the rated continuous working voltage. Acceleration factors for

several operating conditions are determined, allowing calculation

of the time to failure at the working voltage of interest. The values

shown in Table 14 summarize the peak voltages for 50 years of

service life in several operating conditions. In many cases, the

working voltage approved by agency testing is higher than the

50-year service life voltage. Operation at working voltages

higher than the service life voltage listed leads to premature

insulation failure.

The insulation lifetime of the ADuM5010 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 19,

Figure 20, and Figure 21 illustrate these different isolation voltage

waveforms.

Bipolar ac voltage is the most stringent environment. A 50-year

operating lifetime under the bipolar ac condition determines

the Analog Devices recommended maximum working voltage.

In the case of unipolar ac or dc voltage, the stress on the insulation

is significantly lower. This allows operation at higher working

voltages while still achieving a 50-year service life. The working

voltages listed in Table 14 can be applied while maintaining the

50-year minimum lifetime, provided the voltage conforms to either

the unipolar ac or dc voltage cases. Any cross-insulation voltage

waveform that does not conform to Figure 20 or Figure 21 must

be treated as a bipolar ac waveform, and its peak voltage must

be limited to the 50-year lifetime voltage value listed in Table 14.

0V

RATED PEAK VOLTAGE

Figure 19. Bipolar AC Waveform

0V

RATED PEAK VOLTAGE

Figure 20. DC Waveform

0V

RATED PEAK VOLTAGE

NOTES

1. THE VOLTAGE IS SHOWN AS SINU SOIDAL FOR ILLUSTRATION

PUPOSES ONLY. IT IS MEANT TO REPRESENT ANY VOLTAGE

WAVEFORM VARYING BETWEEN 0V AND SOME LIMITING VALUE.

THE LIMITING VALUE CAN BE POSITIVE OR NEGATIVE,

BUT THE VOLTAGE CANNOT CROSS 0V.

Figure 21. Unipolar AC Waveform