Datasheet

START
1
Device
CLK
DRDY
DRDY
1
START
CLK
START
2
Device
CLK
DRDY
DRDY
2
START
CLK
DRDY
1
DRDY
2
ADS131E04
ADS131E06
ADS131E08
SBAS561A –JUNE 2012–REVISED APRIL 2013 www.ti.com
MULTIPLE DEVICE CONFIGURATION
The ADS131E0x are designed to provide configuration flexibility when multiple devices are used in a system.
The serial interface typically needs four signals: DIN, DOUT, SCLK, and CS. With one additional chip select
signal per device, multiple devices can be connected together. The number of signals needed to interface n
devices is 3 + n.
To use the internal oscillator in a daisy-chain configuration, one device must be set as the master for the clock
source with the internal oscillator enabled (CLKSEL pin = 1) and the internal oscillator clock brought out of the
device by setting the CLK_EN register bit to '1'. This master device clock is used as the external clock source for
the other devices.
When using multiple devices, the devices can be synchronized with the START signal. The delay from START to
the DRDY signal is fixed for a fixed data rate (see the START subsection of the SPI Interface section for more
details on the settling times). Figure 36 shows the behavior of two devices when synchronized with the START
signal.
There are two ways to connect multiple devices with an optimal number of interface pins: standard mode and
daisy-chain mode. Refer to the Standard Mode and Daisy-Chain Mode sections for details.
Figure 36. Synchronizing Multiple Converters
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