iC-NQC
preliminar y
Rev B1, Page 13/29
13-bit Sin/D CONVERTER WITH SIGNAL CALIBRATION
MAXIMUM POSSIBLE CONVERTER FREQUENCY
The converter frequency automatically adjusts to the
value required by the input frequency and resolution.
This value ranges from zero to a maximum depen-
dent on the oscillator frequency that is set via register
FCTR.
Serial data output
For BiSS or SSI output the maximum possible con-
verter frequency can be adjusted to suit the maxi-
mum input frequency; an automatic converter resolu-
tion step-down feature can be enabled via the FCTR
register. Should the input frequency exceed the fre-
quency limit of the selected converter resolution, the
LSB is kept stable and not resolved any further; the
interpolation resolution halves.
If the next frequency limit is overshot, the LSB and LSB
+1 are kept stable and so on. If the input frequency
again sinks below this frequency threshold, fine reso-
lution automatically returns.
With the programming of CRC6 = 1 a resolution step-
down will be signalled via the BiSS warning bit.
Max. Possible Converter Frequency For Serial Data Output
Resolution
Protocol
Max. Input Frequency
Restrictions
Requirements
at high input frequency
FCTR
Min. Res. bin dec BiSS SSI fin
max
0x0004
X
X
X
X
f(OSC)min / 40 / Resolution –
0x4102
≥
8
X
X
X
X
f(OSC)min / 24 / Resolution Rel. angle error 2x increased
0x4202
≥
16
X
X
X
X
2 x f(OSC)min / 24 / Res.
Rel. angle error 4x increased
0x4302
≥
32
X
X
X
X
4 x f(OSC)min / 24 / Res.
Rel. angle error 8x increased
0x4702
≥
64
X
-
X
X
8 x f(OSC)min / 24 / Res.
Resolution lowered by factor of 2
0x4B02
≥
128
X
-
X
X
16 x f(OSC)min / 24 / Res.
Res. lowered by factor of 2-4
0x4F02
≥
256
X
-
X
X
32 x f(OSC)min / 24 / Res.
Res. lowered by factor of 2-8
0x5302
≥
512
X
-
X
X
64 x f(OSC)min / 24 / Res.
Res. lowered by factor of 2-16
0x5702
≥
1024
X
-
X
X
128 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-32
0x5B02
≥
2048
X
-
X
X
256 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-64
0x5F02
≥
4096
X
-
X
X
512 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-128
0x6302
8192
X
-
X
X
1024 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-256
Notes
*) Calculated with fosc()min taken from Electrical Characteristics, item A01.
Examples*
fin
max
[kHz] at resol.
8192 1024 200
0.16
1.27
6.5
0.26
2.1
10.8
0.53
4.2
21.6
1.06
8.5
43.3
2.1
16.9
-
4.2
33.8
-
8.5
67.7
-
16.9
135
-
33.8
250
-
67.7
-
-
135
-
-
250
-
-
Table 15: Maximum converter frequency for serial data output.
ICHAUS [ IC-HAUS GMBH ]
