Sigma Delta Wideband (Analog Anti
-
Alias)
When Sigma Delta wideband is selected there is always the built
-
in anti
-
alias filter of the Sigma Delta ADC (no digital filter) in the signal path.
Therefore there is always anti
-
alias protection when wideband is selected. Care must be taken as this filter introduces slight overshoots on
square wave or pulse response signals. Signals of sine wave type will not be effected.
Wideband
Characteristic
Sigma delta, optimal frequency response
-
3 dB Bandwidth
100 kHz
±
5 kHz for sample rates 250 kS/s and 125 kS/s
80 kHz
±
5 kHz for all other sample rates
0.1 dB passband flatness
(1)
DC to 20 kHz
Frequency [kHz]
1000
100
10
1
0.1
Frequency [kHz]
Magnitude [dB]
Magnitude [dB]
-150
-130
-110
-90
-70
-50
-30
-10
10
Magnitude [dB]
-0.2
-0.15
-0.1
-0.05
-0.05
0
0.05
0.1
0.15
0.2
1000
100
10
1
0.1
1000
100
10
1
0.1
±1 V Sigma delta wideband overview
±10 V Sigma delta wideband overview
±10 V Sigma delta wideband passband flatness
±1 V Sigma delta wideband passband flatness
0
Magnitude [%]
Magnitude [%]
2.33
1.74
1.15
0.57
-0.57
-1.14
-1.71
-2.28
Frequency [kHz]
1000
100
10
1
0.1
Frequency [kHz]
-150
-130
-110
-90
-70
-50
-30
-10
10
Magnitude [dB]
-0.2
-0.15
-0.1
0
0.05
0.1
0.15
0.2
0
2.33
1.74
1.15
0.57
-0.57
-1.14
-1.71
-2.28
Figure L.48:
Representative Sigma Delta Wideband examples
(1)
Measured using a Fluke 5700A calibrator, DC normalized
GEN3i
I3763-3.1 en HBM: public
1103
