AD2S1210 LOS and DOS threshold calculation

Hi Experts!.

It`d be nice if someone explains me how can I calculate LOS and DOS thresholds for AD2S1210 which is working in next conditions. 
1. Resolver executed using EXC output from  AD2S1210 at 5 KHz which is buffered and amplified by OPA so the resulting execution voltage is 3.8 Vp-p  (+- 1.9 V). 
2. Coefficient of the  resolver 0.575 at selected execution frequency. 
3. Resolver outputs directly connected to AD2S1210 inputs SIN/SINL COS/COSL. As it`s written in datasheet AD2S1210 introduces Vref/2 offset to its inputs.
(I confirm this, if disconnect resolver from ether AD2S1210 SIN/SINL or COS/COSL inputs this voltage can be measured by multi-meter on `em in relation to AGND. In my case 1.21Vdc. )

So as I suppose input voltages have next configuration: Max amplitude  3.8Vp-p * 0,575 = 2.18 Vp-p which are offset by 1.21V. At 90 degrees sin voltage has 1.21V-(2.18/2)V =  0.12V min value and 1.21V + (2.18/2)V = 2.3V max value and the same for cos input voltage but at 0 degrees. 
Min amplitude of sin signal since sin(0) = 0 just equals Vref/2 voltage and min amplitude of cos signal at 90 degrees is the same Vref/2. 

Also, in my case system dosen`t rotate all the time, most of time it stays steady at some position.

Thanks for any help! 

P.S. Input signals a little violate datasheet at minimum voltage 0.15V but now it`s working fine excepts faults detection which I`m trying to configure right. 



Information was extended.
[edited by: Gans at 2:17 PM (GMT 0) on 9 Sep 2019]