Speedfit Synchronous FET Current in Boost Converter

MattO

Good afternoon, I have been looking at the speedfit DCDC application of the synchronous boost converter. The device currents graph does look quite right.

This is using a duty of 0.75, and as you would expect the current rises in the primary device unitl it turns off at which point i would expect all of that current to then be conducted in the synchronous diode into the capacitor, however as can be seen form the plot below the red trace doesn't have the same current, but much smaller.

Can someone explain what is going on here, is the red trace as i would expect as the current in both the FET and diode?

Thanks

Currents.png

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

Urvi_Ahluwalia

Hi MattO,

Thank you for your question. The red trace here is the current flowing through the synchronous MOSFET, while the green trace is the current flowing through the bottom MOSFET. We have identified an error in the synchronous MOSFET current amplitude. We are actively working on it to verify and correct the waveform, if needed. Please be patient as it may take a few days to implement the updates on SpeedFit.

Thank you,

Urvi