Datasheet
START
DRDY
CS
SCLK
DIN
ADS13xE0x
(Device 0)
START
DRDY
CS
SCLK
DIN
ADS13xE0x
(Device 1)
START
(1)
a) Standard Configuration
CLK
CLK
INT
GPO0
GPO1
SCLK
MOSI
Host Processor
MISO
CLK
START
DRDY
CS
SCLK
DIN
ADS13xE0x
(Device 0)
START
DRDY
CS
SCLK
DIN
ADS13xE0x
(Device 1)
b) Daisy-Chain Configuration
CLK
CLK
INT
GPO
SCLK
MOSI
Host Processor
MISO
CLK
0
DOUT
1
START
(1)
DOUT
0
DOUT
1
DAISY_IN
0
DAISY_IN
1
DOUT
0
ADS131E04
ADS131E06
ADS131E08
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SBAS561A –JUNE 2012–REVISED APRIL 2013
Standard Mode
Figure 37a shows a configuration with two devices cascaded together. Both devices are an ADS131E0x (eight-
channel) device. Together, they create a system with 16 channels. DOUT, SCLK, and DIN are shared. Each
device has its own chip select. When a device is not selected by the corresponding CS being driven to logic 1,
the DOUT of this device is high-impedance. This structure allows the other device to take control of the DOUT
bus. This configuration method is suitable for the majority of applications.
Daisy-Chain Mode
Daisy-chain mode is enabled by setting the DAISY_IN bit in the CONFIG1 register. Figure 37b shows the daisy-
chain configuration. In this mode SCLK, DIN, and CS are shared across multiple devices. The DOUT pin of
device 1 is connected to the DAISY_IN of device 0, thereby creating a daisy-chain for the data. One extra SCLK
must be issued between each data set. Also, when using daisy-chain mode, the multiple readback feature is not
available. Short the DAISY_IN pin to digital ground if not used. Figure 2 describes the required ADS131E0x
timing shown in Figure 37. Data from the ADS131E0x appear first on DOUT, followed by a don’t care bit, and
finally by the status and data words from the second ADS131E0x device.
When all devices in the chain operate in the same register setting, DIN can be shared as well and thereby
reduce the SPI communication signals to four, regardless of the number of devices. Furthermore, an external
clock must be used.
(1) To reduce pin count, set the START pin low and use the START serial command to synchronize and start conversions.
Figure 37. Multiple Device Configurations
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