The continuous dc-current "sinking" capability is determined by the external system-level open-drain (or push-pull) drivers that are interfaced to the TCA39416 I/O pins. Since the high bandwidth of these bidirectional I/O circuits is used to facilitate this fast change from an input to an output and an output to an input, they have a modest dc-current "sourcing" capability of hundreds of micro-Amps, as determined by the internal 10-kΩ pullup resistors.

The fall time (t_fA, t_fB) of a signal depends on the edge-rate and output impedance of the external device driving TCA39416 data I/Os, as well as the capacitive loading on the data lines.

Similarly, the t_PHL and max data rates also depend on the output impedance of the external driver. The values for t_fA, t_fB, t_PHL, and maximum data rates in the data sheet assume that the output impedance of the external driver is below V_OL on both sides.