SI88240ED-IS Datasheet, PDF (26/48 Pages) Silicon Laboratories – QUAD DIGITAL ISOLATORS WITH DC-DC CONVERTER

Si88x4x
3.3.1. Supply Bypass
The Si88xx family requires a 0.1 µF bypass capacitor between all VDDx and their associated GNDx. The capacitor
should be placed as close as possible to the package. To enhance the robustness of a design, the user may also
include resistors (50–300  ) in series with the inputs and outputs if the system is excessively noisy.
3.3.2. Output Pin Termination
The nominal output impedance of an isolator driver channel is approximately 50 , ±40%, which is a combination
of the value of the on-chip series termination resistor and channel resistance of the output driver FET. When driving
high-impedance terminated PCB traces, output pins should be source-terminated to minimize reflections.
3.4. Fail-Safe Operating Mode
Si88xx devices feature a selectable (by ordering option) mode whereby the default output state (when the input
supply is unpowered) can either be a logic high or logic low when the output supply is powered. See Table 11 and
Table 13 for more information.
26
Preliminary Rev. 0.6