OPA2673: Capacitive Coupling on to AC lines

Joe DiBartolomeo

Part Number: OPA2673

All,

I have seen SBOA120 and was wonder if there is a similar app note using capacitive coupling; I am coupling a low data rate signal onto AC line for PLC.

Thanks,

Regards,
Joe

over 5 years ago

0 Hasan Babiker31 over 5 years ago

TI__Genius 15565 points

Hello Joe,

Can you clarify? The App note you referred to includes AC coupling caps at both the inputs & outputs of the circuit (see figure 9).

Best,

Hasan Babiker

0 Joe DiBartolomeo over 5 years ago in reply to Hasan Babiker31

TI__Expert 3115 points

Hi Hasan,

Yes, there are capacitors on the input/ output however the coupling to the AC line is inductive, so I assume there would be some modification to the circuit if the coupling to the AC line were capacitive, maybe not.

Also wondering if capacitive coupling had been tried before.

Thanks,

Regards,

Joe

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Joe,

the transformer is really essential for the mains voltage coupling. It should not be omitted:

sboa130a.pdf

Kai

0 Chris Krasnichuk1 over 5 years ago in reply to kai klaas69

TI__Prodigy 640 points

Hi All,

While the transformer is essential for mains voltage coupling (120/220VAC) what about low voltage AC? (~24VAC)

Or more broadly speaking: Is there a way to accomplish signal coupling while avoiding the use of a transformer? (Hence the capacitive coupling question)

Chris

0 Hasan Babiker31 over 5 years ago in reply to Chris Krasnichuk1

TI__Genius 15565 points

Hello Chris,

The design wouldn't much modification to the circuit in the use case you are describing here. The main concern here would be ensuring you have proper filtering so that the AC voltage doesn't reach the outputs of the amplifier.

Best,

Hasan Babiker

Amplifiers

Amplifiers forum

OPA2673: Capacitive Coupling on to AC lines