Ashkan, The pin capacitance for the ADS1118 digital pins is modeled in the ADS1118 IBIS model. You can find the model here: www.ti.com/.../sbam083 For information about the IBIS model structure, you can find information in this document: www.ti.com/.../snla046.pdf In the model, the capacitance for each pin is shown as a combination of C_pkg and C_comp. The capacitance for the digital lines are approximately 1.5 to 2pF each. There is some difference between the DGS and RUG packages, and the RUG capacitance will be a bit smaller. I would note that the PCB trace lines often have more capacitance than the device themselves. Joseph Wu
↧