am8192b RLS, am8192b Datasheet - Page 7

• Manufacturer Part Number: am8192b
• Description: Angular Magnetic Encoder Ic
• Manufacturer: RLS

Data sheet
AM8192BD01_05
Issue 5, 14
Interpolator
The fast converter changes sine and cosine signals into angle position data. The resolution, hysteresis and
output direction are selectable. It calculates an arctangent function from a ratio between the sine and cosine
signal. The amplitude of the sine and cosine signal therefore is not important as long they are the same.
Angle position data is output as an absolute value via the SSI interface and in incremental A QUAD B signals
simultaneously.
Available binary resolutions:
*
** See Fig. 6. Figures are for highest values of oscillator frequency (f
Incremental output
There are three signals for incremental output: A, B and Ri. Signals A and B are quadrature signals, shifted by
90°, and signal Ri is a reference mark. The reference mark signal is produced once per revolution. The width
of the Ri pulse is 1/4 of the quadrature signal period and it is synchronized with the A and B signals. The
reference mark is positioned at 0° (where the sine signal amplitude is 0 and the cosine signal amplitude is at
its maximum value).
Fig. 6 shows the timing diagram of A, B and Ri signals with CW rotation of the magnet and positive counting
direction. B leads A for CW rotation. The counting direction can be changed by swapping the A and B signals
or by programming the EEPROM with negative counting direction settings.
The transition distance (t
limited by the interpolator and the limitation is dependent on the output resolution. The counter must be able
to detect the minimum transition distance to avoid missing pulses.
© 2009 RLS d.o.o.
Binary
res.
8192
4096
2048
1024
512
256
128
64
32
Figures are for worst case (high temperature, low power supply voltage) values of oscillator frequency (f
th
Res. in
degrees
0.0439°
0.0879°
0.1758°
0.3516°
0.7031°
1.4062°
2.8125°
5.625°
11.25°
January 2009
Max. input
freq. *
0.63 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
TD
) is the time between two output position changes. The transition distance time is
Fig. 6: Timing diagram for incremental output
Minimal
t
122 ns
146 ns
293 ns
585 ns
1.17 µs
2.34 µs
4.68 µs
9.36 µs
18.8 µs
TD
**
Available decimal resolutions:
osc
A
Dec.
res.
2000
1600
1000
800
500
400
320
200
160
100
80
40
= 83 MHz).
Res. in
degrees
0.18°
0.225°
0.36°
0.45°
0.72°
0.9°
1.125°
1.8°
2.25°
3.6°
4.5°
9°
associate company
Max. input
freq. *
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
1 kHz
osc
).
Minimal
t
293 ns
390 ns
585 ns
780 ns
1.26 µs
1.56 µs
1.95 µs
3.12 µs
3.90 µs
6.24 µs
7.80 µs
15.6 µs
TD
**
7