PCA9306 has the capability of being used with its V_REF1 voltage equal to V_REF2. This essentially turns the device from a translator to a device which can be used as a switch, and in some situations this can be useful. The switch configuration is shown in Figure 8-5 and translation mode is shown in Figure 8-6.

Figure 8-5 Switch Configuration

Figure 8-6 Translation Configuration

When PCA9306 is in the switch configuration (V_REF1 = V_REF2), the propagation delays are different compared to the translator configuration. Taking a look at the propagation delays, if the pull up resistance and capacitance on both sides of the bus are equal, then in switch mode the PCA9306 has the same propagation delay from side one to two and side two to one. The propagation delays become lower when V_CC1/V_CC2 is larger. For example, the propagation delay at 1.8 V is longer than at 5 V in the switching configuration. When PCA9306 is in translation mode, side one propagate lows to side two faster than side two can propagate lows to side 1. This time difference becomes larger the larger the difference between V_CC2 and V_CC1 becomes.