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OPA828: ibias vs freq

[FAE] Andrew Wang
Genius 10685 points

Part Number: OPA828

Hi Team,

Customer wants to double check if this device has stable bias current / offset current below 10MHz? (in buffer config)

In other words, is this device bias current sensitive to input signal frequency?

Customer likes this device low input leakage current spec, thx.

Thanks!

Andrew

  • 0
    TI__Guru* 75111 points

    Andrew,

    Since all input pins of ANY op amp have associated with them common-mode and differential input capacitance, the input bias specifications shown in the datasheet must be DC.

    Therefore, as the Cin input impedance decreases with frequency in line with     . , the IB must increase. 

    In the case of OPA828, the Cin_cm and Cin_diff are 9pF and 6pF, respectively - see below.