Can you please tell me if I can connect a single ended signal to IONI feedback pins? We have a weird feedback device with single ended SSI (essentially SPI). Or should I use RS-485 converter to make a true differential signal?
The reason I’m asking this is that I see some feedback pins for SSI (like GPI3, GPI2) can also accept single ended signals. But I’m not so sure about C- and C+ signals.
Also there is some conflicting specification on Wiki.
1.This schematic shows a 3.3V ESD protection on IO pins:
Although SSI communication is specified as RS422/RS485 which is ±5V or more!
But Clock pins should be output? How does that work?
UP!
Any ideas about the above question?
Hi
I’m sorry for the late reply.
The TVS diode in the schematics it 3.3 V version, which can be used with 5 V signals. The actual clamping voltage is higher enough that there is only marginally larger reverse current. I don’t remember if the actually assembled part is the 3.3 V or 5 V version, however it will work with 5 V encoder.
It’s possible to use single-ended signals.
Kind regards, Esa
Thank you for the reply.
I already tested it and single ended works. Clock is connected directly but data input is connected through similar schematic like here:
https://www.renesas.com/eu/en/document/apn/836-differential-input-accept-single-ended-levels?language=en
The resistor network(R1, R2) shown there will hold the inverting input at 2.5V and the other resistors will decrease the amplitude of the 5V signal.