ADuM4120/1 frequency graph only go to 500 kHz

The resolution of the duty cycle of the ADUM4221 allows for very fine pulse width minimums, but when the operating frequency is brought very high, the quiescent current of the device goes up dramatically.

This quiescent current is too large for recommended operation of the part, therefore the operation should be targeted at sub-MHz frequencies.

Higher frequency operation is possible, but care must be taken to ensure the self-heating of the device is not too large.