Damping affects settling time and overshoot. Standard damping will fit most applications. Double damping eliminates oscillation but settles to the final position more slowly. Some applications may require double damping to average out cyclic motion such as found in moving vehicles. Damping options can be specified when ordering.
- Specifications apply over entire operating temperature range.
- Typical values are specified at Vcc = 12V and 25C.
| Parameter | Min. | Typ. | Max. | Units |
| Supply Voltage |
7.5 |
12 |
16 |
V |
Supply Current @ 12V supply
Active
Sleep |
|
14
2.5 |
18.5 |
mA |
| Analog Output Impedance |
|
51 |
|
Ohms |
| Zero Scale Analog Voltage |
0 |
2 |
12 |
mV |
| Full Scale Analog Voltage |
4.066 |
4.095 |
4.124 |
V |
| Output Noise (Analog version) |
|
10 |
|
mV rms |
| Differential Nonlinearity (Analog version) |
-1.0 |
|
1.0 |
LSB |
| Integral Nonlinearity (Analog version) |
-1.0 |
|
1.0 |
LSB |
| Absolute Accuracy (SEI interface version) |
|
0.18 |
0.25 |
Degrees |
Angle tracking speed
Single-turn mode
Multi-turn mode |
|
|
3600
1800 |
RPM |
| Position Update Rate (1) |
|
|
7 |
msec. |
(1) The internal microcontroller takes a snapshot of the disk every 7 msec. and stores the position in memory. It responds immediately to a "report position request" by sending the most recently computed position.
| Parameter | Default value
| Volatile? |
SEI address
|
0 |
Non-volatile |
| Resolution |
3600 |
Non-volatile |
Origin offset
|
0 |
Non-volatile |
Baud rate
|
9600 |
Volatile |
| Mode |
0 |
(1)
|
(1) Mode is always restored from non-volatile EEPROM on power-up; however, there are separate SEI commands for setting the RAM copy only, or both the RAM copy and the non-volatile EEPROM copy. For an explanation of the Mode bits, see SEI Absolute Encoder Communications Protocol.
The analog version of the A2T has a 12-bit DAC on the output which feeds to 2 lines that are otherwise used for the BUSY handshaking pair. This DAC has a full range of 0 to 4.095V which is 1 mV per count. The absolute position value the internal microcontroller sends to the DAC is the same as the digital value that it sends to the host over SEI. Since the resolution (which represents the number of CPR) is field programmable, the range of the DAC will also follow that setup. The default resolution is 3600 CPR, which yields 1 count per tenth of a degree. This makes the DAC output equal to 1 mV per tenth of a degree or 0 to 3.599V. If you want the DAC to have the full range to 4.095V, set the single turn resolution to 4096. This is easily done with the available software which runs on a PC.
Please Note: The BUSY handshaking lines are replaced by the analog output option. This means that only one device will be able to connect to the SEI bus when using the analog output option.
