I’m confused by the datasheet as it says that the HBVS capacitor is ‘typically’ a 5pF cap. But then there’s a formula on page 19 (formula 10) which, using a FET with a Coss of 230pF and a peak current of 1.6A, states that the HBVS cap should be more than 263pF and with a margin of 2-3 times greater, that would be in the order of 780pF.
These values seem a long way apart.
Hello Tom,
This discrepancy between the typical 5pF and the larger capacitor value on page 19 is due to different operating conditions.
In typical applications this capacitor would be 5pF for more standard operating scenarios. However, the formula on page 19 accounts for noise immunity, frequency response, and ensuring cases where the margin error is more strict, resulting in the formula to be used on page 19, resulting in higher capacitances like 780pF.
Hopefully this provided some insight.
Best,
Krishan