Original question:
TIDA-00364: Number of parallel mosfets required for 5W drive
Hi
We are using CSD19536KCS two MOSFETs in parallel in synchronous boost application. To drive the MOSFETs we have used UCC21222 isolated driver with bootstrap.
So, is this driver is sufficient to drive these two parallel Mosfets?
Hi,
The limitation is usually power dissipation of the driver due to the capacitive load of the gate of the CSD device coupled with the switching frequency.
Sections 9.2.2.6 Estimating Gate Driver Power Loss and 9.2.2.7 Estimating Junction Temperature will guide you on these calculations for your design.
When using MOSFETs in parallel, be careful about parasitic oscillations (may be at extremely high frequency - multi-MHz). To prevent these oscillations from breaking out, it is advisable to use individual gate resistors close to the gate of each power switch as was done in TIDA-00364 as shown below:
Let us know if you have any further questions.
Best regards,
Don
