SPARKY FORUM

AUDIO => VOLT + standalone AMP => Topic started by: nonnoare on June 01, 2017, 01:46:09 AM

Title: TPA 3118 gain setting
Post by: nonnoare on June 01, 2017, 01:46:09 AM

Hi there! I was trying to figure out what the used  gain settings are for the TPA3118 chip.  As per the Texas Instruments documentation,  the gain is set by the combined value of two resistors.  Looking at  your board,  it seems like there is only one 20 Kohm resistor (measured with a tester),  the other connection is left open.  This seems like the 20dB configuration,  but in that case the only resistor installed should be 5.6 Kohm. The 20 Kohm value,  in the T.I. datasheet,  is used in conjunction with a 100 Kohm resistor for the 26dB configuration.
Should I assume that the Volt board is set to an "unconventional"  20dB gain?
Thank you very much.

Title: Re: TPA 3118 gain setting
Post by: sparkyadmin on June 01, 2017, 02:10:55 AM

Hi,

 Our board is set for 20db gain. The setting is R1 5.6K and R2 is open.

With Regards
Sparky admin

Title: Re: TPA 3118 gain setting
Post by: nonnoare on June 01, 2017, 03:31:02 AM

Well... I double checked, and I measure exactly 20 Kohm on the resistor shown on the attached picture... which I believe is R1... or am I mistaken?
Anyway, the board works correctly. Just curious


https://drive.google.com/file/d/0BwGKsgmlTMyNaGl1bXlGeGFZTTQ/view?usp=drivesdk (https://drive.google.com/file/d/0BwGKsgmlTMyNaGl1bXlGeGFZTTQ/view?usp=drivesdk)