SBAU193E June 2011 – May 2021 ADS8568
The ADS8568 ADC uses SPI serial communication in mode 2 (CPOL=1 and CPHA=0). Because the serial clock (SCLK) frequency can be as fast as 45 MHz, the ADS8568EVM offers 47-Ω resistors between the controler and device to aid with signal integrity. Typically, in high-speed SPI communication, fast signal edges can cause overshoot; these 47-Ω resistors slow down the signal edges in order to minimize signal overshoot.