With edge-triggered technology, the current consumption rises with the frequency of the input on both the input and output sides. Therefore, if the input frequency is low, the current consumption can be reduced.

On the other hand, the circuit current on the primary side of OOK (On-Off-Keying) depends on the duty of the signal. The current on the secondary side increases depending on the load and frequency. When it is ON, the carrier wave is continuously sent, so the current consumption is high, but because it is resistant to noise, products using OOK are the mainstream in applications with a lot of disturbance noise, such as automotive products and motors. SKYWORKS isolators are excellent products with low current consumption and data rate of 150MHz while being OOK.

The OOK (On-Off-Keying) method controls the output by sending a signal only when the input is High (or Low). A photocoupler is a similar control method. The good point of this method is that even if the output changes due to disturbance, it recovers immediately. In some SKYWORKS products, there is anoption to send the carrier wave in High or Low depending on the bias of the signal so that the current consumption can be further reduced.

On the other hand, the edge trigger method seen in other companies' digital isolators changes the output state by looking at the input transition (H→L/L→H). Since the current consumption changes according to the input frequency, it is possible to reduce the current consumption, especially when performing low-speed signal communication. In order to communicate the transition signal normally, a filter is provided to prevent disturbance from entering, but there is still a possibility that disturbance will enter, and it may lead to malfunction such as the output being inverted as shown in the left figure. . There are certain countermeasures such as periodically sending a status signal on the input side or sending a different signal on the rising/falling edge, but caution is required in noisy applications.