1. A question about RS-485 AC termination
Customer’s circuit
application note “slla070d”
A parallel termination circuit which is designed by the customer
works well to eliminate noise from power line.
R and C is placed in series in the application note,
otherwise, the customer had placed them in parallel.
Is there any problem or issue ?
device : SN65HVD07
data rate : several kbps
node : 4 to 8
Signal and power lines are tied together in a twisted pair cable.
A common-mode choke coil and TVS diode had also placed, but they did not work enough.
Above AC termination circuit did work well.