INA821: INA821 Small-Signal Response and Gain vs Frequency of G=2000

Akihisa Tamazaki

Part Number: INA821
Other Parts Discussed in Thread: TINA-TI

Hello team,

The customer is interested in INA821 because A single external resistor sets any gain from 1 to 10,000. He is considering G=2000 case, and he would like to know the performance of Small-Signal Response and Gain vs Frequency in case of of G=2000. The customer would be check with TINA-TI, but he would like to know the measurement data if possible before his evaluation. Would you please provide the performance data of G=2000?

Your help would be appreciated.

Best Regards,
Akihisa Tamazaki

over 6 years ago

0 Marek Lis over 6 years ago

TI__Guru 67791 points

INA821 Small-signal -3dB bandwidth for G=2000 is 15kHz - half of the bandwidth for G=1000 (see below).

0 Akihisa Tamazaki over 6 years ago in reply to Marek Lis

TI__Genius 12460 points

Marek-san,

Thank you for your comment.

Do you have the waveform data of G=2000 as below?

Your reply would be so appreciated.

Best Regards,
Akihisa Tamazaki

0 Marek Lis over 6 years ago in reply to Akihisa Tamazaki

TI__Guru 67791 points

Tamazaki-san,

Fig 46 of INA821 datasheet shows a small-signal response to a step voltage input, which has very sharp input edges (within a nano-second), and thus far above the effective bandwidth of the part. For that reason, the output is controlled by the Small-signal Rise Time discussed in TI Precision Labs - see below.

For that reason, for G=2000 the overall shape of the output waveform will not change except for the doubling of the its amplitude - see in red below.

0 Akihisa Tamazaki over 6 years ago in reply to Marek Lis

TI__Genius 12460 points

Marek-san,

Thank you for your comment.
I will learn from the Precision Lab.

Best Regards,
Akihisa Tamazaki

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INA821: INA821 Small-Signal Response and Gain vs Frequency of G=2000