Cascaded H-Bridge Inverter: Stackable Modules to 2kV

Challenge: Generate clean sinusoidal waveforms up to 2kV from a low-voltage DC bus, with variable frequency. The previous linear amplifier approach was massive and ran hot. Solution: Cascaded H-bridge inverter where each stage adds its output voltage in series, reaching 2kV with lower-voltage MOSFETs per module. Identical PCBs stack mechanically and electrically. Staggered switching instants push harmonic content to higher frequencies where it's easier to filter. Inter-stage isolation at 2kV requires isolated gate drivers and strict creepage management. Results: The client now offers 500V, 1kV, and 2kV variants of their instrument using 1, 2, or 4 stacked modules from the same PCB design.