INA129: Is INA129 gain temperature dependent?

Hi Khoi,

Thank you for your post. The INA129 output will certainly change with temperature. This is shown in table 7.5 Electrical Characteristics of the datasheet as a drift term:

-Tamara

Does this offset voltage only cause bias at the output? I mean, it will not create a different gain at the output right?

Let say I have a sine wave across a resistor. The rise in temperature only affects the sine wave DC shift, but not the amplitude, right?

Thanks.

Khoi Ly10 said:

Part Number: INA129

Hi everyone,

I have a sine wave going through a circuit of R and C in series.  R = 20kohm, C = 300pF. The sine wave signal is 20V pk-pk at 1kHz.

I connect the +in and -in of the INA 129 at the two sides of the resistors. So, the +in reads the sine wave input 20V pk-pk and the -in reads what ever the voltage drop across R.

I leave Rg pins on the INA129 floating (gain = 1 based on the formula provided in the datasheet)

What I see is some drifts at the INA129 output. When I place the heat gun near the circuit, the output signal increases. When I place the heat gun away from the circuit, the output signal decreases. 

Is the internal gain of the INA129 temperature dependent? or it is some quirk from my capacitor/resistor?

Thanks,

Khoi Ly

Hello,

Can you quantify the increase/ decrease/ drift that you're observing?

Thanks,

Avish

Hi Khoi,

We haven't heard from you in a few days. I hope we were able to resolve your question. I am going to close this thread now, please feel free to reply if you have any further questions to re-open.

-Tamara