Isolated communication system

An isolated communication system comprising a transmission unit, a receiving unit which is isolated from the transmission unit and an isolated communication unit which provides isolation between the transmission unit and the receiving unit and provides signal transmission between the transmission unit and the receiving unit, in which a digital input signal that transitions between a first level and a second level different from the first level is transmitted from the transmission unit to the receiving unit via the isolated communication unit;

• the transmission unit including:
• an edge pulse generating circuit configured to detect a transition of the digital input signal from the first level to the second level and generate a corresponding first pulse and configured to detect a transition of the digital input signal from the second level to the first level and generate a corresponding second pulse;
• and
• a transmission pulse signal generating circuit configured to generate a pulse corresponding to a clock signal having a predetermined cycle during a period of time in which the digital input signal remains at the second level, and add the pulse corresponding to the clock signal to the first and the second pulses generated in the edge pulse generating circuit to generate a transmission pulse signal having pulses corresponding to a plurality of clock signals, the pulses existing between the first pulse and the second pulse each generated in the edge pulse generating circuit;
• the receiving unit being configured to decode a received pulse signal based on the transmission pulse signal received from the transmission unit via the isolated communication unit, as a signal that transitions from the first level to the second level when an initial pulse of the received pulse signal is detected and that transitions from the second level to the first level when a subsequent pulse is not detected within a predetermined first time period from when a most recent pulse of the received pulse signal is detected.