Does AD2S1205 has any disadvantage when use it only for getting input sine and cos information ? We are wondering synthetic reference generation which is described in Datasheets may not work well and effect to processing accuracy for input, when not using(or not connecting) excitation output for resolver, doesn't it ?
The synthetic reference improves performance and accuracy by reducing the phase shift between the excitation and the sine, cosine inputs.
If you are not using the excitation from the AD2S1205 you need to synchronize the AD2S1205 excitation to the source excitation.
The procedure is
1. The devices must be clocked with the same signal from the same clock source (CLKIN input)
2. The excitation frequency should be configured the same.
3. Issue a hardware reset on the AD2S1205 to synchronize the AD2S1205 excitation to the source.
This ensures that the excitation signals from all devices are synchronized. The synthetic reference will then be able to correctly demodulate the input signals.