ZHCSQT2 March 2024 ADS127L18
ADVANCE INFORMATION
Daisy chain mode packs data from two or more devices into one set of DOUT pins. In daisy chain mode, the DOUT pins of one device connect to the DIN pins of a second device from which the data is read. The data of the first device are shifted out after the data of the second device. The DP_DAISY bit of the DP_CFG1 register enables the DIN pins for daisy chain operation. If not enabled, DIN data are ignored and original channel data are repeated until new data are available. The main clock and DCLK frequency of daisy chained devices must be the same. This requires an external clock input.
Figure 7-37 shows a daisy chain connection of two ADS127L18 devices in TDM mode. In this example, four DOUT pins are programmed, resulting in 16 channels of data packed into four DOUT pins. Synchronize the ADCs to align the conversion periods. A minimum DCLK signal frequency is necessary to read the entire data set within a conversion period and the maximum value is listed in the SpecificationsSpecificationsSpecifications section. Figure 7-38 shows the data stream format.