We have a design proposal for a 8 ch power and data isolated RS232 interface using 3 Analog Devices circuits:
- 3.3V/3.3V system
- ADM3311 3/5 ch RS232 driver
- ADUM5401 isopower and 4ch (3/1) data
- ADUM1440 isodata 4ch (0/4) data micropower
5401 feeds both 3311 and 1440 with iso 3.3V
Is this robust regarding power demand or is too small power margin to withstand iso 3.3V (3.0V) in all situation? I understand the three RS232 Tout load resistors 3 kohm at remote site have big influence.
What happen if load is 0 ohm and +-12V puts on three Touts (such a pin/wire failure in DB connector)?