iC-NQI
13-bit Sin/D CONVERTER WITH CALIBRATION
Rev A2, Page 13/26
MAXIMUM CONVERTER FREQUENCY
The converter frequency automatically adjusts to the down feature can be enabled via the FCTR register.
value necessary for the input frequency and resolution. Should the input frequency exceed the frequency limit
This value ranges from zero to a maximum dependent of the selected converter resolution, the LSB is kept
on the oscillator frequency which can be set using reg- stable and not resolved any further; the interpolation
ister FCTR.
resolution halves.
Serial data output
If the next frequency limit is overshot, the LSB and the
For serial data output the possible maximum converter LSB+1 are kept stable and so on. When the input fre-
frequency can be adjusted to suit the maximum in- quency again sinks below this frequency limit, the fine
put frequency; an automatic converter resolution step- resolution automatically returns.
Maximum Converter Frequency For Serial Data Output
Resolution
Protocol
Max. Input Frequency
Restrictions
Examples*
Requirements
at high input frequencies
finmax [kHz] at resol.
8192 1024 200
FCTR
Min. Res. bin dec BiSS SSI finmax
0x0004
0x4102
0x4202
0x4303
0x4602
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
fosc()min / 40 / Resolution
fosc()min / 24 / Resolution
2 x fosc()min / 24 / Res.
4 x fosc()min / 32 / Res.
4 x fosc()min / 24 / Res.
8 x fosc()min / 24 / Res.
16 x fosc()min / 24 / Res.
32 x fosc()min / 24 / Res.
64 x fosc()min / 24 / Res.
128 x fosc()min / 24 / Res.
256 x fosc()min / 24 / Res.
512 x fosc()min / 24 / Res.
–
0.16
0.26
0.53
0.78
1.27
2.1
4.2
6.2
8.5
16.9
33.8
67.7
135
250
-
6.5
≥ 8
Rel. angle error 2x increased
Rel. angle error 4x increased
Rel. angle error 8x increased
10.8
≥ 16
≥ 32
≥ 32
21.6
32.0
Resolution lowered by factor of 2 1.1
-
-
-
-
-
-
-
-
0x4A02 ≥ 64
0x4E02 ≥ 128
-
Res. lowered by factor of 2-4
Res. lowered by factor of 2-8
Res. lowered by factor of 2-16
Res. lowered by factor of 2-32
Res. lowered by factor of 2-64
Res. lowered by factor of 2-128
Res. lowered by factor of 2-256
2.1
-
4.2
0x5202
0x5602
≥ 256
≥ 512
-
8.5
-
16.9
33.8
67.7
135
0x5A02 ≥ 1024
0x5E02 ≥ 2048
-
-
0x6202
Notes
4096
-
-
*) Calculated with fosc()min taken from Electrical Characteristics item A01.
Table 14: Possible maximum converter frequency for serial data output.
ICHAUS [ IC-HAUS GMBH ]
