IC-MR Datasheet, PDF (18/44 Pages) IC-Haus GmbH – 13-BIT S&H SIN/COS INTERPOLATOR WITH CONTROLLER INTERFACES

iC-MR 13-BIT S&H SIN/COS
preliminary
INTERPOLATOR WITH CONTROLLER INTERFACES
OPERATING MODES
Rev A1, Page 18/44
In order to calibrate iC-MR, to adjust the input signals,
as well as to test iC-MR the operation mode must be
altered. The operating mode can be selected by us-
ing the register MODE. The output functions of PSO,
NSO, PCO and NCO change according to the various
operating modes.
MODE(1:0)
ADR 0x0F; bit 1:0
MODE(4:2)
ADR 0x10; bit 2:0
Code Operating mode
Pin PSO Pin NSO Pin PCO Pin NCO
0x00 Normal operation *
PSO
NSO
PCO
NCO
0x01 Analog 1
PS_W
NS_W
PC_W
NC_W
0x02 Analog 2
SVDC
CVDC
VREFI
IBP
0x03 Bypass
PSI
NSI
PCI
NCI
0x04 iC-Haus internal
...
0x1F iC-Haus internal
Note: *) Measurement condition: ENOCC = 1, ENOCM = 1, TIIN = 0, TIPOL = 0, TLDOS = 0
Table 7: Operating mode
Calibration modes
In operation mode Analog 1 the adjusted sine and co-
sine signals are being provided (PS_W, NS_W, PC_W
und NC_W). In operation mode Analog 2 bias cur-
rent source (IBP), reference potential input (VREFI),
as well as center potentials of calibration circuits for
sine (SVDC) and cosine (CVDC) can be measured.
BIAS CURRENT SOURCE AND SIGNAL FILTER
Bias current source
The calibration of the bias current source in operating
mode Analog 2 is required for adherence to the given
Electrical Characteristics and instrumental in the deter-
mination of the chip timing (e.g. SCL clock frequency).
For adjusting the bias current source, the voltage drop
is being measured using a 10 kΩ resistor from pin NCO
to pin GNDA. The setpoint of 200 µA is reached with a
measurement voltage of 2 V.
Signal filter
In order to decrease the adjusted analog signals’ noise
iC-MR uses a signal filter which can be activated
through register bit ENF.
ENF
Code
0
1
Addr 0x0F, bit 2
Function
Signal filter deactivated
Signal filter active
Table 9: Signal filter activation
CFGBIAS
Code k
(signed)
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
Addr 0x0F, bit 7:4
IBP
∼
31
31−k
100 %
103 %
107 %
111 %
115 %
119 %
124 %
129 %
Code k
(signed)
0x8
0x9
0xA
0xB
0xC
0xD
0xE
0xF
IBP
∼
31
31−k
79 %
81 %
84 %
86 %
88 %
91 %
94 %
97 %
Table 8: Adjustment of bias current source
Low pass cutoff frequencies can be adjusted using
SELBP.
SELBP
Code
0
1
Addr. 0x0F; bit 3
Function
7.5 kHz
15 kHz
Table 10: Signal filter cutoff frequency (fin < 10 Hz)
The filter’s dead band can be activated using NEFDR.
NEFDR
Code
0
1
Addr. 0x0C; bit 3
Function
Filter dead band active
Filter dead band deactivated
Table 11: Signal filter dead band