Part Number: DRV612
Dear TI apps team,
I wonder if you could answer a quick question about an application requiring DC isolation between two pieces of equipment (one with audio output, one with audio input).
Both equipments will be connected to the same battery but customers can (and do) connect equipment power the wrong way round. They also often have a relaxed attitude to the need for fuses.
Source equipment has reverse polarity protection but receiver may not.... even if it does, a fault current path exists through any common ground between equipments. We would like to capacitively couple the audio feeds and return as shown.
The high value resistor is there to bleed away any difference that might accumulated between ground potentials when the equipments are operated from truly separate power sources although I'm concerned that it might cause more trouble than it's worth in the event that a shared power supply application develops a ground connection fault. Primary concern is whether the audio or DRV operation would be impaired with the total capacitive coupling.
I've considered the option of an audio transformer but this is a cost sensitive application, and we would like to maintain the cable drive capability of the DRV612.
We have an understanding of the input impedance of the receiving equipment and would choose the value of the capacitors to suit.
many thanks
