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AD8334 - Consequences of Exceeding the Input Voltage

Question asked by flyerrap18 on Mar 5, 2013
Latest reply on Mar 11, 2013 by flyerrap18

     Good afternoon.  I have an A&D customer that is looking to replace the TI VCA2615.  One of the parts under consideration is the AD8334.  On page 25 of the data sheet, it states that "... the maximum input signal before saturation is ±275 mV or +550 mV p-p.  Overload protection ensures quick recovery time from large input voltages.  Because the inputs are capacitively coupled to a bias voltage near midsupply, very large inputs can be handled without interacting with the ESD protection."

 

     The customer needs something that has more control over the LNA instead of the fixed gain LNA in the AD8334.  The VCA2615 has this feature.  One option is the consideration of using a separate LNA and using that output to VGA of the AD8334.

 

QUESTION 1:  Does ADI make such a part as I did not find one using the Compass selection tool?

 

QUESTION 2:  How high of an input voltage can the part handle before interacting with the ESD protection?

 

QUESTION 3:  If they bypass the LNA and go straight into the VGA, what is the maximum input voltage on this stage before it is saturated?  Also, what is the maximum input on this stage after saturation but prior to any damage or ESD protection kicking in?

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