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Can the output of AD8370 be DC-coupled to the input of AD9286

Question asked by ADCfan on Feb 20, 2013
Latest reply on Feb 22, 2013 by J.Harris

I am trying to find a variable gain amplifier for AD9286.  The variable gain amplifer should have bandwidth greater than 280MHz, DC coupled, and support +3.3V. It looks like that only AD8370 meets this requirement.  However, according to the datasheets, the output common-mode voltage of AD8370 is set to midsupply +1.65V and does not seem to be adjustable, but the input common-mode voltage of AD9286 is set to +1.4V.

 

Questions:

1) Can they be connected directly? I could not find the CMRR parameter of AD9286 in the datasheet.

2) As indicated in the datasheet, the input span of AD9286 is 1.2V and the input common-mode voltage is 1.4V. Does this mean the input can go up to 1.4+1.2/2 = 2.0V, which is higher than the power supply (1.8V) of AD9286.

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