Isolated DC/DC Converter and Signal Isolation

What you found is one option with 2 digital data channels.

This is the actually smallest combination available on the market.

For only one data channel the only option would be a DC/DC only - like ADuM5010 combined with a single channel iCoupler like ADuM1100/3100. But from the cost and space point the dual channel part is more of interest.

But be aware the ADuM5240 is a 1st generation isoPower part - efficiency is better on a  ADuM520x.

Joseph:

The no load current of the ADuM5240 is very high at about 80mA, due to the less efficient 1st generation isoPower architecture. 

The next generation isoPower ADuM5200 can much more output current at 100mA, and has a typical no load current of about 8mA, but comes in the wide body SOIC-16 package, which is 3 times bigger than the narrow body SOIC-8 of the ADuM5240.

The newer ADuM5210 is in a small SSOP 20 pin package, a bit bigger than the narrow SOIC-8 of the ADuM5240, but has much lower no load current of only 6.8mA Vs 80mA for the ADuM5240.  If you can use the package of the ADuM5210 it would consume much less current and not run hot like the ADum5240 would.

Regards, Brian

On which side of the ADuM5210 is your Micro placed?

The ADuM5210 as most of the isoPower parts can run under the following supply conditions:

Input = 5V    - Viso = 5V

Input = 5V    - Viso = 3.3V

Input = 3.3V - Viso = 3.3V

Thank you very much for your help.

It looks like I am going to go with the ADuM5210 as suggested.

My last question is that it seems for the Logic Inputs I will need a minimum of .7*V(iso) to get my high signal? I believe my controller will be sending a 3.3 Volt signal, but my Viso will be 5 volts.

Will I be able to achieve a logic high output with a 3.3 Volt (or lower) signal for the ADuM5210?

Yes, according to the data sheet the logic input high level threshold is 0.7 VDD1 - so for 5V it is 3.5V.

This is what we guarantee.

But from reading your details, it may be more appropriate to do something like done in the CN-0196 and use one of the appropriate isolated Gate-Drivers. I.e. ADuM3223 !?

But be aware that in the Circuit Note the used Micro is only working with a 2.5V supply!

So the ADuM5210 will be operating with Input 5V, Viso 5V.

It will be supplying an isolated voltage and digital signal to a gate driver for a half bridge configuration.

The microprocessor will be on the "left" or un-isolated part of the design/5210.

Looking at the datasheet I am not certain what kind of communication signal I can have going in/out of the isolator such that it operates appropriately. Will I need the PWM signal to provide 3.5 volts such that the communication signal goes through?