SBAS988 November 2023 ADC34RF55
PRODUCTION DATA
The internal ADC architecture is sensitive to temperature changes. The ADC34RF55 contains two additional internal ADC cores (one for channel A/B and one for channel C/D) which are used when one of the ADCs is in calibration. ADCs are calibrated as pairs where one ADC at a time is connected to the internal calibration DAC. The calibration is configured via SPI register writes and is executed using SPI register writes or using the GPIO1 pin. When executed, the calibration takes approximately 23 ms x 3 GSPS / FS per ADC pair (approximately 11.5 ms x 3 GSPS / FS per ADC). The example in Figure 6-15 shows 2x internal averaging where 4 ADC cores (#1,2,3,4 for chA/B and #6,7,8,9 for chC/D) are used in operation and ADCs #5 and #10 for calibration.