I'm using the ADuM4221 as a gate-drive for a synchronous buck converter. It's implemented according to the bootsrapped Half Bridge Operation Circuit found in Figure 38 in its datasheet (ADuM4221/ADuM4221-1/ADuM4221-2 (Rev. B) (analog.com)), with a few minor tweaks.
Fig. 1 - Ref. from Datasheet
Fig.2 - My implemented circuit
It works fine when operating the converter. However, when I try to set both VIA input = LOW and VIB INPUT= LOW, the VOB output will still be kept HIGH. This keeps the low-side MOSFET on, which is unsuitable for my application.
The truth table for this device (Table 11 in datasheet) says it should keep both VOA and VOB outputs LOW when both VIA and VIB inputs are being kept LOW, which is the case. The disable pin still works as intended and sets both outputs to LOW.
What am I doing wrong? Thank you in advance