TPA6120A2

Hi Frankie,

It's interesting. Could you please check the following questions?

1 For your supply VCC=+-12V, you use DC souce in lab or DC-DC devices on board?

2 Could you please capture the waveform of input/out put/ +-12v?

Best Regards,

RomanWang

Look like loading effect playing a role on it. 

640mV input will become 500mV when connecting the modified EMV

here are the waveforms

Input waveform 

output waveform 

+12V input voltage

-12 input voltage

anything on TPA6120 side I can do to lower to loading effect? It is not possible for adding a input buffer on my design 

Thanks

Frankie

Hi Frankie,

I agree with you there is somewhere havve loading effect.

For the input side, Could you increase the input 200ohm, but keep the feadback resistor less than 10K. to see the effect?

Fort the output side, the 10ohm is for isolate capatance load, what application will you use? doesn 't it possiable have big capatance?

the feedback resistor on the current design is 2K. And currently I using 300 Ohm resistor load for preliminary testing. So I dont know the capacitance play role on my problem.

BTW, Is it ok to increase the feedback resistor to 10K? Per datasheet it recommended less than 2K. 

Also, does TI have spice model of the amp for simulation?

Thanks

Frankie

Hi Frankie,

The design of the feedback resistor is a trade off of noise and stability.

So to deal with the loading effect, increase the input resistor and feedback resistor at the same time.

Unfortunately, we do not have a SPICE model for this device.

-d2

Is this still the case, because a spice model would be really handy

I was researching the site for a spice model as well. Ditto the thought.