KCC Quizzes AQQ303 about the radius of a circle
1. Quote of the month: "When I die, I want to die like my grandfather who died peacefully in his sleep. Not screaming like all the passengers in his car" - Will Rogers
2. Quiz AQQ304 about finding the radius of a circle
Good luck, and try to be
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August Monthly Blog Quiz! Read the blog, take the quiz, and you could win a gift card
Important: Read the blog first . The quiz questions are all based on the content of the blog:
Stay in the loop and win! Read the blog Current Output Driving Industrial Loops , then take our quick five-question quiz for a chance to win a gift card
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ADM2565E
Recommended for New Designs
The ADM2561E, ADM2563E, ADM2565E, and ADM2567E are 3 kV rms signal and power isolated RS-485 transceivers. These devices are designed for balanced transmission...
Datasheet
ADM2565E on Analog.com
Hi Mike,
Sorry for the late response.
For ease of reading I report here the datasheet of the ADM2565E:
ADM2561E/ADM2563E/ADM2565E/ADM2567E (Rev. B) (analog.com)
As you rightly noted, this device has a VIO logic flexible I/O supply separated from VCC to allow communication with interfaces at different voltages. In particular, the VIO supply accepts a supply voltage between 1.7 V and 5.5 V, allowing communication with 1.8 V, 2.5 V, 3.3 V, and 5 V devices. In your case, as anticipated by you, I suggest to connect VIO (pin 7) to 3.3V to have this voltage level on RxD and TxD, matching the voltages of the FPGA.
For further information you can consult the paragraph "1.7 V TO 5.5 V VIO LOGIC SUPPLY" on page 23 of the datasheet.
Talking about the isolated power supply, when Vsel = Visoout, the Viso set point is 5.0 V. Considering that your bus works at that level, I suggest to use this setting. You can find the Vsel pin function description in table 12 of the datasheet (page 12).
Finally, assuming that Viso = 5V for your application, it is recommended that VCC is connected to 5V.
Table 14 of the datasheet (page 20), shown also below for simplicity, summarizes the possible configurations of the isolated DC-DC Converter with the associated voltage range needs.

I hope I have been helpful and clarified your doubts. If you have any other questions do not hesitate to contact us.
Good work,
Andrea