Adding a headphone jack to a TDA7053A

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neverused
Posts: 290
Joined: Fri Feb 06, 2009 6:14 pm

Adding a headphone jack to a TDA7053A

Post by neverused »

I've built my audio amp with a TDA7053A, but the data sheet only makes provision for two speakers. I honestly cannot think of any other solution to add a headphone jack, other than to use a DPDT switch to choose between the speakers and jack. I have the link to the datasheet and was wondering if anyone else had a better idea?

Thanks!
nitro2k01
Posts: 651
Joined: Tue Dec 19, 2006 12:41 pm

Re: Adding a headphone jack to a TDA7053A

Post by nitro2k01 »

The TDA7053A is sort of unsuitable for driving as headphones are using a common negative terminal, whereas the TDA7053A expects two speakers with individual neg. and pos. terminals. You can probably drive headphones with it too, by connecting both the negative terminals of the TDA7053A to a common point with resistors, but it's not right™.

My advice is...
Use a headphone jack with a bypass function to silence the amplifier when needed. Depending on the configuration you may need to add an inverting transistor.
You could then possibly drive the headphones with the signals hat come out from your portable (or whatever). If the source signal is too weak to drive headphones you may need a second amplifier. Also, the downside of this method is that you can't control the headphone amplitude without either using a double ganged potentiometer or redesigning the reference circuit. Realistically you're going to need an additional amplifier circuit for the headphones as well.
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Last edited by nitro2k01 tomorrow, 1:48 pm; edited 1 time in total
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