iC-NQ
13-bit Sin/D CONVERTER WITH CALIBRATION
Rev D1, Page 13/25
MAXIMUM POSSIBLE CONVERTER FREQUENCY
The converter frequency automatically adjusts to the tion step-down feature can be enabled via the FCTR
value necessary for the input frequency and resolution. register. Should the input frequency exceed the fre-
This value ranges from zero to a maximum dependent quency limit of the selected converter resolution, the
on the oscillator frequency which can be set using reg- LSB is kept stable and not resolved any further; the
ister FCTR.
interpolation resolution halves.
Serial data output
If the next frequency limit is overshot, the LSB and the
For BiSS or SSI output the maximum possible con- LSB+1 are kept stable and so on. When the input fre-
verter frequency can be adjusted to suit the maxi- quency again sinks below this frequency limit, the fine
mum input frequency; an automatic converter resolu- resolution automatically returns.
Max. Possible 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
0x4304
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
f(OSC)min / 40 / Resolution
–
0.16
0.26
0.53
0.64
1.27
2.1
4.2
5.1
8.5
16.9
33.8
67.7
135
250
-
6.5
≥ 8
f(OSC)min / 24 / Resolution Rel. angle error 2x increased
10.8
≥ 16
≥ 32
≥ 64
2 x f(OSC)min / 24 / Res.
4 x f(OSC)min / 40 / Res.
4 x f(OSC)min / 24 / Res.
8 x f(OSC)min / 24 / Res.
16 x f(OSC)min / 24 / Res.
32 x f(OSC)min / 24 / Res.
64 x f(OSC)min / 24 / Res.
Rel. angle error 4x increased
Rel. angle error 8x increased
21.6
26.0
Resolution lowered by factor of 2 1.1
-
-
-
-
-
-
-
-
0x4A02 ≥ 128
0x4E02 ≥ 256
-
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
2.1
-
4.2
0x5202
0x5602
≥ 512
-
8.5
≥ 1024
-
16.9
33.8
67.7
135
0x5A02 ≥ 2048
0x5E02 ≥ 4096
-
128 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-64
256 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-128
512 x f(OSC)min / 24 / Res. Res. lowered by factor of 2-256
-
0x6202
Notes
8192
-
-
*) Calculated with fosc()min taken from Electrical Characteristics item A01.
Table 14: Maximum converter frequency for serial data output.
ICHAUS [ IC-HAUS GMBH ]
