date

page

04/2010

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DATA Sampling:

Position data is read from the AMT devices inside the encoder every 120 μs; it takes approximately 30 μs to

transfer a byte of information so the breakdown is:

1) issue sample command: 30 μs

2) read 2 bytes of data: 60 μs

3) calculate, add zero offset, and save position: 30 μs

The position inside the AMT device is sampled at the end of step 1, and it is 0 to 25 us delayed at that point. So

the data inside the microprocessor is 95 to 120 μs delayed from the actual rotor position.

The SPI interface is capable of 2 MHz operation, and the data read operation consists of a command byte followed

by 3 or 4 byte read operations; this is 12 to 16 μs at the 2 MHz interface speed.

So there is a delay of 95 to 120 μs for the data to be ready, and a delay of 12 or more μs for the user to transfer

data from the encoder interface.

phone 503.612.2300

fax 503.612.2380 www.cui.com

PART NUMBER:

DESCRIPTION:

AMT203

12 BIT ABSOLUTE ENCODER