Q8 gate drive via half bridge driver via not sufficient

[martinjaeger]

Already in previous MPPT designs, the reverse blocking MOSFET (here: Q8) was supplied via the low-side gate driver of the half bridge, switching it on automatically when the power stage is on.

In this design the reverse blocking MOSFET can be used also as a dump load switch for wind turbine applications (with the generator negative connected via separate terminal W-), so it should be possible to switch it on even if the power stage is off. R12 allows to supply power directly from the 12V rail.

Unfortunately, the 10k pull-up resistor R45 necessary for this use case prevents the MOSFET Q8 to stay on if powered by the low-side driver, especially at low duty cycles.

Preliminary solution:

• Populate 0R resistor R12 (leading to slightly higher power consumption when power stage is off)
• Replace R45 with a 0R resistor (solder bridge) and remove R12 and T6