No, the refresh pulses are internal to the iCoupler devices. In the absence of
logic transitions at the input for more than ~1 μs, a periodic set of refresh
pulses indicative of the correct input state are sent
to ensure dc correctness at the output. If the decoder receives no internal
pulses for more than about 5 μs, the input side is assumed to be unpowered or
nonfunctional, in which case the isolator output is forced to a default state
(see Table 15 on datasheet for default states) by the watchdog timer circuit.