AD2S80A busy Timing

Document created by analog-archivist Employee on Feb 23, 2016
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I read the AD2S80A's datasheet, and I have questions about the Digital Timing.

1. When BUSY Pin is low, I can read the conversion data. How long BUSY Pin hold
low, then I can read the data? Because if the input to the converter changes
continuously, then there will be pulses in the BUSY Pin, then when I can read
the data.
2. If ByteSelect is high, and if the position Data is Data0~Data15, then
whether these data will occur in the data bus like below shown:

Bus      DB1  DB2 DB3 DB4 DB5 DB6 DB7 DB8  DB9 DB10 DB11 DB12  DB13   DB14 DB15
Position Data            Data15 Data14 Data13 Data12 Data11 Data10 Data9 Data8 
Data7  Data6 Data5  Data4  Data3   Data2    Data1   Data0
3. DATA LOAD Pin is LO, DB1~DB16 is input pin. When DB1~DB16 is input pin, how
should I use them?


1. The Busy output is initiated each time the internally generated position
data changes by 1 LSB. It means that the frequency of the Busy pulses depends
on the rotation speed of a resolver. In situation when resolver is rotating
continuously you may control /INHIBIT input to stop data transfer from the
up-down counter to the output latches to provide enough time to the
micro/dsp/fpga to read the data.
2. Yes, the order you have shown is correct.
3. The Data Load mode should be used when the AD2S80A works as the Control
Transformer and the Data input pins are used to feed the ratio multiplier of
the AD2S80A. Please find more information on how to feed ratio multiplier in
the AN-203 application note: