TPA2039D1: TPA2039 Gain

Hi Sundy xie,

The internal resistance value is 150KΩ, so you can calculate the gain with the next formula: G= (2*150KΩ)/Ri. You need an external resistor of 31.5kΩ in order to get 9.5dB. But this device is designed to work with a 12dB fixed gain.
You can have a look the TPA2011D1. This device has the same functionality and pinout as the TPA2039D1. Besides, this device has the function of configurable gain.

Best Regards
José Luis Figueroa
Audio Applications Engineer

Dear Luise,

They used TPA2011D1 in the old product. Now because of cost issue, we recomend TPA2039 to them.

Do you mean the internal resistor of TPA2039 is the same with TPA2011D1?

And we can get 9.5DB gain by using TPA2039 with an external 31.5k resistor,right?

Best regards,

Sundy

Hi Sundy,

Yes, the internal resistor is the same.
That's right, you need a 31.5KΩ external resistor to get a 9.5dB gain.

Best Regards
José Luis Figueroa
Audio Applications Engineer

Dear Jose,

Could you help to check the unit of this  formula?

I think it should be V/V , not DB;

Gain=20log(2Rf/Ri) db

If Rf=150KΩ，Fixed gain=12db; Ri should be 75.38kΩ.

Sundy xie