When the input power or input signal is lost, the default output of a digital isolator with suffix F is low, while the default output without suffix F is high.
Both models do not have a VIO power supply, but the difference is that the input logic of SiLM1042 is TTL level, while the input logic of SiLM1044 is CMOS level, so the input voltage of SiLM1044 is higher
