Is it ok to use in combination with ADuM3165 ?

Question

Hi all.
Looking at the ADuM3165 datasheet (www.analog.com/.../adum3165-adum3166.pdf) from Table 1 I can see that in High-Speed the maximum current consumption IDD2 is 69 mA and VDD2 is used for the internal 3V3.
Looking at the ADuM5028 and ADuM5020 datasheets (https://www.analog.com/media/en/technical-documentation/data-sheets/adum5020-5028.pdf)the minimum output current at 5V and below 85°C is 60mA for ADuM5028, while this is 50mA or 100mA (not very clear here !?) fot the ADuM5020. Anyway in the ADuM3165 datasheet at page 21 of 27 it is written: 1. Approximately 48 mA or 59 mA per side for idle or busy high speed USB connections, respectively.
So the final question is: just connecting a USB device to side 2 of the ADuM3165, is it correct to use the ADuM5028-5BRIZ to generate the 5V for VDD2 supply input ?
Or should I use the ADuM5020-5BRIZ (even if the 50mA / 100mA is not clear) ?
Or both solutions (always with VSEL pin connected to VISO pin forcing the +5Viso output) should be good ?
Thank you for support
Ambrogio

TommyMoran · Accepted Answer

Hi Ambrogio, 
 Thanks for your question. Let me clarify the Iiso spec. The 60mA min value in the electrical specifications is for IISO(MAX). What we are trying to communicate here is that we guarantee, at minimum, a max load current of 60mA with VISO regulating between 4.75 and 5.25. In other words you can have at least a 60mA load on VISO while being within 5% of the regulation setpoint. 
 For ADuM5020, it is the same story, so guaranteed VISO within 5% of regulation set point with at least a 50mA load, within 10% with a 100mA load. 
 With the max current consumption of the ADuM3165 being 69mA, I would recommend using the ADuM5020 as this surpasses the maximum rated output power of the ADuM5028. Unless you know the ADuM3165 will not enter high speed mode in your application, and ambient operating temp will always be less than 85degC. Only if those conditions were guaranteed would I recommend ADuM5028 
 Regards, 
 Tommy)

AmbrogioB · Answer

Thank you very much Tommy for your answer. You clarified me that if I have on isolated side a 75 mA USB device The VISO output should be in the range 4.5V ... 5.25 V (10%). My real case is that the USB device on side 2 that I need to isolate will run only in High-Speed Mode (480 Mbit/s); but at the same time I need to generate the 5.0V VISO only to supply the side 2 internal 3V3 because the USB device in side 2 bring only GND2, DD+ and DD- (+5V is not provided from the USB device); otherwise, if I understood correctly, the IDD2 limit of 69 mA refers to VDD2 (3.3V) so not to the 5.0V output for VISO, so the IBUS2 shoud be less than 50mA. 
 What do you think about this ? Am I wrong ? Best Regards Ambrogio

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Is it ok to use in combination with ADuM3165 ?

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