Hi All;
I have an existing mixer circuit that uses an LM386 as the final stage. This has been redesigned to use the TDA7052A. The output of the circuit is to a speaker microphone which, in the original design uses the same ground point as the speaker for the transmit function (a short to ground when you press the transmit button).
The TDA7052A however uses an (open drain?) to ground for the negative terminal of the speaker. Can anyone tell me if this is a constant source to ground for the speaker? Will I intermitantly lose the path to ground for my speaker microphone function as the 7052's internal opamp's do there thing? I don't have a TDA7052 in DIP to breadboard this.
Thought I'd throw it out here.
I have an existing mixer circuit that uses an LM386 as the final stage. This has been redesigned to use the TDA7052A. The output of the circuit is to a speaker microphone which, in the original design uses the same ground point as the speaker for the transmit function (a short to ground when you press the transmit button).
The TDA7052A however uses an (open drain?) to ground for the negative terminal of the speaker. Can anyone tell me if this is a constant source to ground for the speaker? Will I intermitantly lose the path to ground for my speaker microphone function as the 7052's internal opamp's do there thing? I don't have a TDA7052 in DIP to breadboard this.
Thought I'd throw it out here.
Yeah this is what I see as well. I have a very bad feeling that while the speaker will operate normally, the push to talk will fail without a direct path to ground and I see no way around it short of rewiring the mic and thats not a viable option. This project is (was) ready for PCB however I noticed this possible design flaw just recently. Without testing it I can't be sure it 'won't' work but it looks doubtful. I think I have a serious problem.
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