ADS5296A Datasheet, PDF (89/107 Pages) Texas Instruments – 10-Bit, 200-MSPS, 4-Channel and 12-Bit, 80-MSPS, 8-Channel Analog-to-Digital Converter

ADS5296A
www.ti.com
SBAS631 – OCTOBER 2013
Digital Averaging
The device includes an averaging function where the ADC digital data from two (or four) channels can be
averaged. The averaged data are output on specific LVDS channels. Table 61 shows the combinations of the
input channels that can be averaged and the LVDS channels on which the averaged data are available.
Table 61. Using Channel Averaging
AVERAGED CHANNELS
1, 2
1, 2
3, 4
3, 4
1, 2, 3, 4
1, 2, 3, 4
5, 6
5, 6
7, 8
7, 8
5, 6, 7, 8
5, 6, 7, 8
OUTPUT WHERE
AVERAGED DATA ARE
AVAILABLE AT
OUT1
OUT3
OUT4
OUT2
OUT1
OUT4
OUT5
OUT7
OUT8
OUT6
OUT5
OUT8
REGISTER SETTINGS
Set AVG_OUT1 = 10 and EN_CHANNEL_AVG = 1
Set AVG_OUT3 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT4 = 10 and EN_CHANNEL_AVG = 1
Set AVG_OUT2 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT1 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT4 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT5 = 10 and EN_CHANNEL_AVG = 1
Set AVG_OUT7 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT8 = 10 and EN_CHANNEL_AVG = 1
Set AVG_OUT6 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT5 = 11 and EN_CHANNEL_AVG = 1
Set AVG_OUT8 = 11 and EN_CHANNEL_AVG = 1
Performance with Digital Processing Blocks
In applications where higher SNR performance is desired, digital processing blocks (such as averaging and
decimation filters) can be used advantageously to achieve higher performance. Table 62 shows the improvement
in SNR that can be achieved compared to the default value, using these modes.
Table 62. SNR Improvement Using Digital Processing
MODE
Default
With decimate-by-2 filter enabled
With decimate-by-4 filter enabled
With two channels averaged
With four channels averaged
TYPICAL SNR (dB)⁽¹⁾
70.4
75.4
76.7
75
75.8
TYPICAL IMPROVEMENT IN
SNR (dB)
NA
5
6.3
4.6
5.4
(1) In all modes (except default), 14x serialization is used to capture data.
Copyright © 2013, Texas Instruments Incorporated
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