AnsweredAssumed Answered

Sin / Cos clipping fault with unbalanced + / - amplitudes

Question asked by andy_hvcd on May 1, 2018
Latest reply on May 11, 2018 by andy_hvcd



I am using the AD2S1210 part with a tamagawa singlsyn resolver (which has no rotor windings) which unfortunately does not seem to produce complimentary (i.e. equal but opposite) waveforms on sin+ and sin- or cos+ and cos-. However, the differential signals (i.e. between sin+ and sin - and between cos+ and cos-) are correct. The result of this is that the resolver to digital converter is working correctly with regards to interpreting the position and speed etc. however, the fault register is reporting that the sin / cos inputs are clipping.


My understanding from the datasheet is that the 4 inputs are eached checked against the rails and that if they are within 0.15 to 0.2V of the ground or AVdd respectively for 4us then the fault is set. However, I assume the + and - signals for each channel are fed into a differential amplifier and it is the output of this that really needs to be within a particular range.


So my question is, am I right in assuming that I can ignore this fault so long as the differential of the input signal is no more than 4Vpp? Even if the sin + and - signals exceed 2Vpp at times?