IC-MSA Datasheet, PDF (21/29 Pages) IC-Haus GmbH – SIN/COS SIGNAL CONDITIONER with AGC and 1Vpp DRIVER

iC-MSA SIN/COS SIGNAL
preliminary
CONDITIONER with AGC and 1Vpp DRIVER
SIGNAL CONDITIONING CH1, CH2
Rev A1, Page 21/29
The voltage signals necessary for the conditioning of
channels 1 and 2 can be measured in operation mode
Calibration 2.
Gain Settings CH1, CH2
The gain is set in four stages:
1. The automatic gain control is shut down (set register
AGCOFF to a value of 1).
2. The gain range is selected so that the differential
signal amplitude of CH1 is closest to 1 Vpp (signal Px
vs. Nx, see Figure below).
GR12
Code
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
Addr 0x46, bit 2:0
AGC on (AGCOFF = 0)
0.20 .. 2.77
0.34 .. 4.69
0.51 .. 7.03
0.71 .. 9.82
1.01 .. 13.8
1.28 .. 17.7
1.68 .. 23.2
2.11 .. 29.1
AGC off (AGCOFF = 1)
0.75
1.27
1.89
2.65
3.73
4.77
6.24
7.83
Table 24: Gain Range CH1, CH2 with voltage divider
inputs (RIN12=0x9)
3. The automatic gain control is turned on (set register
AGCOFF to a value of 0) and adjust ADJ to obtain a
signal amplitude of 1 Vpp for CH1.
4. The CH2 signal amplitude can then be adjusted rel-
ative to the CH1 signal amplitude via gain correction
ratio GC2.
AGC gain range reserve can be checked by the value
of read-only register AGCGF1 which represents the 8
most significant bits of the current automatic gain set-
ting for channel 1.
NB: automatic gain control is halted during AGCGF1
readout and will continue automatically afterwards.
0.25 Vp
0.25 Vp
1 Vpp
iC-MSA
Px
Vpk(Px)
Nx
Vpk(Nx)
GND
R0
Vpeak-to-peak
Figure 6: Definition of 1 Vpp signal. Termination R0
must be high-ohmic during all Test and
Calibration modes.
GR12
Code
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
Addr 0x46, bit 2:0
AGC on (AGCOFF = 0)
0.80 .. 11.1
1.36 .. 18.8
2.04 .. 28.1
2.85 .. 39.3
4.02 .. 55.4
5.14 .. 70.8
6.73 .. 92.6
8.44 .. 116
AGC off (AGCOFF = 1)
2.98
5.06
7.58
10.6
14.9
19.1
25.0
31.3
Table 25: Gain Range CH1, CH2 (RIN12=0x9)
GC2
Code
0x00
0x01
...
0x80
...
0xFE
0xFF
Addr 0x4F, bit 7:0
Ratio
0.8292
0.8304
GC2−128
20 2047
1.00
GC2−128
20 2047
1.2025
1.2043
Table 26: Gain Correction Ratio CH2/CH1
AGCGF1
Value
0xF0
0x80
0x5E...92
0x4B...B4
0x33...CD
0x10
Addr 0x59, bit 7:0
AGC reserve
alarm (±0.0 dB)
0.27 .. 3.7 (±11.4 dB)
0.33 .. 3.0 (±9.5 dB)
0.50 .. 2.0 (±6.0 dB)
0.67 .. 1.5 (±3.5 dB)
alarm (±0.0 dB)
Table 27: Minimum AGC Reserve (read only)