ADL5567 input bias current

Hi,

Could you share a bit more detail on your application ?   Our EVB shows ac coupling to the input pins, but are you intending to use the part in DC coupled state ?   If so, what V common mode are you needing at the input ?

Thanks,

Darrell

Hi Darrell,

Thanks for your quick reply!  I'm currently using the ADL5566 as a pre-driver for an ADC (i.e. ADC12D1600).  The op amp is used in single-ended input mode.  The VIN input has only a 28ohm pull-down.  The VIP input is connected to a 50ohm signal generator and has a 75ohm pull-down.  If the signal generator is DC-coupled (or if the VIP input is terminated with a 50ohm resistor), the ADL5566 output has no DC offset.  However, if the signal generator is AC-coupled (or if the VIP input is left floating), the ADL5566 input impedance are unbalanced and the op amp output has a small DC offset due to the input bias current.  I'm considering switching the op amp for a new op amp with a lower input bias current.  I've notived the ADL5567 is footprint-compatible and seems to be an improvement on the ADL5566.  However, the datasheet doesn't mention about the input bias current but the preliminary datasheet says the input bias current is still TBD.

Thanks,

Patrice

Hi Patrice,

See the attached datasheet, Rev A, along with a draft document for further explanation of the dc coupled mode.

Thanks,

Darrell

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