Datasheet

CH1
DOUT1
( )ADS1274
CH2 CH3 DINCH4
SCLK
DRDY
(SPI)
FSYNC
(Frame-Sync)
1 2
24
2523 48 4947 72 7371 96
97
95
CH1
DOUT1
( )ADS1278
CH2 CH3 CH5CH4
CH8 DINCH7
169 191 192 193 194 195168167
CH2
DOUT1
( )ADS1274
CH4 DIN
SCLK
DRDY
(SPI)
FSYNC
(Frame-Sync)
1 2
24 2523 48 4947
50
CH2
DOUT1
( )ADS1278
CH4 CH5 CH8 DIN
143 144 145 145 146121120
CH7
119
ADS1274
ADS1278
SBAS367F –JUNE 2007–REVISED FEBRUARY 2011 www.ti.com
TDM Mode, Fixed-Position Data TDM Mode, Dynamic Position Data
In this TDM data output mode, the data position of In this TDM data output mode, when a channel is
the channels remain fixed, regardless of whether the powered down, the data from higher channels shift
channels are powered down. If a channel is powered one position in the data stream to fill the vacated data
down, the data are forced to zero but occupy the slot. Figure 79 shows the data stream with channel 1
same position within the data stream. Figure 78 and channel 3 powered down.
shows the data stream with channel 1 and channel 3
powered down. Discrete Data Output Mode
In Discrete data output mode, the channel data are
shifted out in parallel using individual channel data
output pins DOUT[4:1]/[8:1]. After the 24th SCLK, the
channel data are forced to zero. The data are also
forced to zero for powered down channels. Figure 80
shows the discrete data output format.
Figure 78. TDM Mode, Fixed-Position Data (Channels 1 and 3 Shown Powered Down)
Figure 79. TDM Mode, Dynamic Position Data (Channels 1 and 3 Shown Powered Down)
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