JAJSGW2A January 2019 – May 2019 ADS1260-Q1 , ADS1261-Q1
PRODUCTION DATA.
Figure 58 shows a example of an AC-excited bridge measurement system. The example shown omits optional filter components for clarity. The transistors switch the bridge excitation voltage by drive signals provided by the GPIO drivers through the analog input pins. The timing of the drive signals are synchronized to the ADC conversions. The drive signals do not overlap in order to avoid bridge commutation during the switching phase of the drive signal. The transistors gate resistors bias the transistors off at power-on. At host start-up, the host configures the ADC to the AC-excitation mode. See Figure 7 for timing of the drive signals.
The recommended sequence AC-excitation configuration is as follows:
Start the conversions. Adjust the time delay parameter as necessary based on the time constant of the input and reference filters.