PCM1808-Q1: Min value of input impedance

Shinji Tsuji

Genius 15204 points

Part Number: PCM1808-Q1

Hi team,

Could you advise the minimum value of Analog input impedance of PCM1808-Q1?

regards,

over 5 years ago

0 Collin Wells over 5 years ago

TI__Guru 64595 points

Tsuji-san,

The typical input impedance is 60kΩ and while there is not a specified minimum, the process variations of these resistors will be +/-15-20% worst-case with a typical 1-sigma distribution of +/-5%.

0 Zak Kaye over 5 years ago in reply to Collin Wells

TI__Mastermind 23050 points

Hi Tsuji-san,

I would also like to add that the input impedance does actually vary with sample rate. For a typical curve of this, please refer to this thread: https://e2e.ti.com/support/audio/f/6/p/963547/3559654#3559654

0 Shinji Tsuji over 5 years ago in reply to Collin Wells

TI__Genius 15204 points

Hi Collin,

Do you mean the worst case minimum is 60kohm -5% = 57kohm or

60kohm -20% = 48kohm?

Or worst case 48kohm, 1sigma distribution 57kohm?

regards,

0 Collin Wells over 5 years ago in reply to Shinji Tsuji

TI__Guru 64595 points

Hello,

The number previously provided represent estimated standard distributions of a Guassian (normal) distribution. +/-20% deviations will be very uncommon as the probability calculations of these events would indicate.

1-sigma = +/-5%: 57kΩ - 63kΩ

4-sigma = +/-20%: 48kΩ - 72kΩ

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PCM1808-Q1: Min value of input impedance