Question
My task is to design an interface for a resolver. My problem is that the
information in the datasheet does not clearly defines this. See AD2S1210-EP
table 1 for the sine,cosine inputs. There is an amplitude required of 2.3 till
4 Vpp. In case of a direct connection of the resolver windings (see datasheet
AD2S1210 page 19) and the electrical resolver representation on page 15, there
are voltages possible of approx. 0Vpp.(for example sine 0°, cosine 90°).
Could I use the RDC in this configuration or is a special signal conditioning
necessary?
Another question to the accuracy: my requirement to the static accuracy shall
be less than +/-0,008rad. Is this possible?
Answer
There is no special circuitry required to interface between a resolver and the
AD2S1210. The AD2S1210 is designed to be directly connectable to a resolver.
Another way to read the specification would be that the maximum input signal
amplitude should be within the 2.3 V to 4.0V range. At 0'degrees sine is 0 V,
this is ok as long as when sine is at its maximum, @90'Degrees, that the peak
to peak amplitude is within the 2.3V to 4.0V range.
Accuracy of +/-0.008rad is +/-27.5 arc minutes. The AD2S1210-EP data sheet
list a worst case accuracy of +/-7 + 1LSB arc minutes.
For the respective resolutions this equates to the following : see table.gif
(attached).
The requirement of +/-0.008 rad is achieved for the AD2S1210-EP at 12-bit and
greater resolution.