PSpice A/D accuracy in V16.3?

 Did some simulation with high dynamic range (using a SUM ABM Model : adding a constant value of 1 with a sinus-wave having 120nV as amplitude) . I was supprized getting quantized data with a LSB of 60nV which corresponds to single precision (mantissa hase 23 + 1Bits). Is there any chance to get double precision?

Here my sim settings:

****     OPTION SUMMARY
******************************************************************************
  OPTS
DC ANALYSIS -

    ITL1 =  150
    ITL2 =   20
  RELTOL =    1.0000E-03
  ABSTOL =    1.0000E-12
   VNTOL =    1.0000E-09
    GMIN =    1.0000E-12
VLTEXPLIMIT =     .5    

TRANSIENT ANALYSIS -

    ITL4 =   10
TSTEPDIVFACTOR =    8
  CHGTOL =   10.0000E-15
DMFACTOR =    1      
FSTDELFACTOR =    1      

MISCELLANEOUS -

  NUMDGT =   10
   WIDTH =   80
    DEFL =  100.0000E-06
    DEFW =  100.0000E-06
   DEFAD =    0      
   DEFAS =    0      
    TNOM =   27       

 Thanks!