AD2S1210 Input buffer recommendation


I am using the AD2S1210 to convert resolver signals to encoder signals.  I have been able to get the chip to work with a standard resolver.  I now want to use it with a resolver with a ratio of 40:1.  The return signal is 0.2mVpp.  The AD2S1210 wants SIN and COS signals 3.15Vpp.  I can't boost the EXC signal anymore, so I need to boost the SIN and COS signals.  Are there any recommended circuits for boosting the SIN and COS signals that play well with the input of the AD2S1210?  Is there any more info on the inputs besides what is in the datasheet that would help design a boost circuit?  The circuits I've tried so far haven't worked well enough so far.