4.2 Sampling rate reduction (binary decimation)
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Acqiris SA240P User's Manual
4.2 Sampling rate reduction (binary decimation)
A programmable binary decimation can be used to lower the sample rate (See table below).
Sampling rate reduction can be used in both digitizer and averager acquisition mode.
Decimation Ratio
Resulting sampling
rate
No
4 GS/s
2
2 GS/s
4
1 GS/s
8
500 MS/s
16
250 MS/s
Table 4.1
- List of selectable sampling rates.
The decimation can be used in digitizer or averaging mode. The zero-supress mode is not
compatible with the sampling rate reduction (binary decimation).
To enable decimation, user should set the sampling rate to required decimated sampling rate.
Decimation and bandwidth limitation
The table below provides the behavior when combining decimation and bandwidth limitation.
Decimation
factor
Effective
sampling
rate
Bandwidth
(typical)
bandwidth filter applied vs. Bandwidth limited (BWL)
None
BWL=700 MHz BWL=200 MHz
BWL=20 MHz
1
4 GS/s
2 GHz
No filter
BWL=700
MHz
BWL=200 MHz
BWL=20 MHz
2
2 GS/s
920 MHz
Filter for decim-
ation factor = 2
BWL=700
MHz
BWL=200 MHz
BWL=20 MHz
4
1 GS/s
450 MHz
Filter for decim-
ation factor = 4
Filter for
decimation
factor = 4
BWL=200 MHz
BWL=20 MHz
8
500 MS/s
237 MHz
Filter for decim-
ation factor = 8
Filter for
decimation
factor = 8
BWL=200 MHz
BWL=20 MHz
Table 4.2
- Behavior and applied filter when combining decimation and bandwidth limitation.
