TLV8544: Inquiry: TLV854x input impedance spec

Ting Ye

Part Number: TLV8544

Hello Team,

In TLV854x datasheet, the input impedance in page 6 shows differential and common mode are 2pF and 4pF respectively.
Could you help add input differential and common mode resistance? Although TLV854x is a CMOS op amp which has large impedance, we still want to have input impedance spec to see if there will be load effect in sensor AFE application.

Thank you.
Regards,
Ting

over 6 years ago

0 kai klaas69 over 6 years ago

Guru 140200 points

Hi Ting,

the input resistances are in the TOhm range (1T = 1000G = 1 000 000 Meg).

Kai

0 Chuck Sins over 6 years ago in reply to kai klaas69

TI__Mastermind 24330 points

Ting

I am working with design to obtain values for you. As Kai mentioned, it is large but let me see what I can obtain for you.

Chuck

0 Ting Ye over 6 years ago in reply to Chuck Sins

TI__Genius 11800 points

Hello Kai, Hello Chuck,

Thank you for the prompt supports!

Regards,
Ting

0 Chuck Sins over 6 years ago in reply to Ting Ye

TI__Mastermind 24330 points

Ting
I looked at our characterization data for Ibias and IOS to calculate common mode and differential input impedance.
On the average, I see both common mode and differential input impedances being greater than 10T ohms (> 10^14 ohms).
Chuck

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TLV8544: Inquiry: TLV854x input impedance spec