TPA3116 Power Amp

[mortron]

I have recently acquired a TPA3116 Board and amp looking to put it to use. My desire was to build it as a power amplifier and use something upstream to control volume. From what I've read, the TPA3116 is 30K ohm input, and I can wire the inputs directly to the inputs on the board. Is this correct? If so, would both grounds go to the centre G pin on the board? Thanks in Advance.

 

[impuls60]

The input resistance varies with the chosen gain( the manufactures gain setting decides the input resistance/impedance. You can find the details in Texas instrument site in a downloadable pdf. It can be as low as 9k ohm and upwards to 60k ohm, but 26db =30kohm in the datasheet. If you wan't more gain you can change 2 resistors so it will play loud from a cellphone. Its all in the pdf..
Both grounds go to the G pin yes( signal ground is most likely tied to psu/boards ground. That works fine for most uses🙂
Its recommended to have speakers connected when you power the board up. Other than that the chip is bulletproof!

 

[mortron]

Thank you very much. I am already learning.

So looking at the board there is a 20k and 100k resistor right next to each other, the only two near pin 8 on the IC, so I am willing to bet there is 26db of gain and that the input impedance is 30K.

Do I understand this correctly? If so, this amplifier seems to be a great way to learn on the cheap. Many thanks.

 

[irribeo]

and each input has a 10k resistor to ground...

 

[mortron]

and each input has a 10k resistor to ground...

Thank you. I see those on the board now. What is their intended purpose in the circuit? While the datasheet is useful, it would have been nice to get a schematic with the board. Apologies for all the stupid questions.

Was my previous post above correct in my logic?

Thanks

 

[impuls60]

Yes those resistors are usally for gain setting. On some of these tpa boards I've also noticed there is used a 100k resistor for something else. Perhaps Irribeo can confirm it for you?