does anybody know the value of the pull-up / pull-down resistors which set the Default value on the Si866x devices when one side is not powered?
The Si866x are digital CMOS output devices and do not need pull-up or pull-down resistors. The default state for the output, when the input side is unpowered, is set by which device is used. Si866xB devices default to low, and Si866xE device default to high. This is covered in the Tables 12 and 13 of the datasheet.
In Table 12 of the datasheet, footnote number 6 states, "... For default high devices, the data channels have pull-ups on inputs/outputs. For default low devices, the data channels have pull-downs on inputs/outputs."
What value pull-up / pull-down resistors are employed internal to the chip for Si866xE / Si866xB, respectively? I'm having trouble with impedance matching of output pin A6 on Si8661BC-B-IS1 (VDD1 = 3.3V, VDD2 = 5V).
It is a pullup/down current ( 2.0μA typ.) than a resistor at inputs. The output impedance ZO is 50ohm typ.