SCPS267B March 2017 – February 2020 TCA9803
Selecting the pull-up resistor required for the A-side is well documented already, see the I2C Bus Pullup Resistor Calculation application report. The rest of this section deals only with selection of a device based on the B-side design requirements.
Selection process of each device is identical to the procedure described in the Device Selection Guide section, except that it must be done for each individual TCA980x. This section jumps straight to the selection graphs to show the selection process. See the Detailed Design Procedure section for single device for detailed information.
As shown in Figure 30, the shaded region is the appropriate region based on design requirements listed in Table 7. Any line that touches this shaded region is able to meet the design requirements. In this example, the TCA9803, TCA9802, and TCA9801 are able to satisfy the design requirements, since they all touch the shaded region. The TCA9800 falls below the shaded region.
Based on the selection graph shown above, the TCA9801 is selected, since it is the lowest-power device which touches the shaded region (red trace). The TCA9803 or the TCA9802 may also be used without any consequences.