in reply to: HART MAU section? posted by Sima Tarashion on 24 November 2004 at 08:38:09.
I'm not quite sure which filter component values you are missing. I simulated the receive circuit in the Smar Research app note and found that it didn't match it's description as it has a very poor knee response. It probably works well enough in practice though. I think the transformer circuit should work too, but finding a good, cheap transformer is a pain. The opto transmit switch is a nuisance too, if you are on a tight power budget.