SDG #278 Assembling and Testing the High Current MOSFET driver

This episode moves the high current MOSFET driver project from schematic to working hardware. The newly delivered boards are inspected first, with attention to the copper pour, gate trace routing and pad geometry, all of which matter more than usual on a board expected to move large gate charges at speed. Assembly is then walked through component by component, which is useful for anyone building something similar who wants to see the practical order of operations for mixed passive and power parts.

The validation is the most instructive part. First power-up is treated cautiously, checking that the driver behaves sensibly before anything is loaded. The board then goes on a Picoscope 5000 series so that the gate waveforms can be examined properly: rise and fall times, edge quality, overshoot and ringing, and whether the driver is actually delivering the peak current the design promised. This is the sort of measurement that separates a driver that works on paper from one that will switch a large MOSFET cleanly without overheating it in the linear region.

A thermal camera pass follows, which is a quick and effective way to spot components dissipating more than expected, marginal current paths or a driver IC working harder than intended. Thermal imaging on a freshly built board frequently reveals problems that an oscilloscope trace will not.

The closing section considers where the design goes next, including the limits found during testing and the changes worth making on a revision. It is a realistic view of how much measurement is needed before a gate drive board can be trusted.