9.3.1 Refresh Enable

The ISO7041 uses an edge based encoding scheme to transfer an input signal change across the isolation barrier versus sending across the DC state. Enabling the refresh feature consistently validates that the DC output state of each isolator channel matches the DC input state. An internal watchdog timer monitors for activity on the individual inputs and transmits the logic state when there is no input signal transition for more than 100 µs. This ensures that the input and output state of the isolator always match. Tie both EN1 and EN2 to their respective grounds to enable refresh.

Disable refresh by tying both EN1 and EN2 to their respective VCC power supplies. Disabling refresh will further decrease the power consumption of the device but the DC state is not guaranteed at startup. System level solutions can be implemented to ensure the isolator channel output matches the input at startup. For example, at start up, an immediate full transition of the input signals from high to low and low to high on the individual isolator lines would allow the states of the outputs to properly track the inputs.