GaN-Based 4-MHz Full-Bridge Electrosurgical Generator Using Zero-Voltage Switching Over Wide Load Impedance Range

In this article, a 4-MHz full-bridge inverter system for an electrosurgical generator (ESG) is presented with zero-voltage switching (ZVS) turn-on over a wide load impedance range based on wideband gap material gallium nitride (GaN) technology. The proposed resonant circuit is used for impedance matching and limits the current when the load is short state while performing ZVS over a wide load impedance range. It also ensures high power performance at high frequencies for electric surgery. The implementation methods of the GaN switch at 4 MHz with high output performance are guided by the low inductance from the gate-driver output to the switch gate node and the effective heating management structure of the GaN-based inverter. The proposed generator achieved a maximum output power of 99 W to the load and a maximum overall efficiency of 89% with overcurrent of
Source: IEEE Transactions on Biomedical Circuits and Systems - Category: Biomedical Engineering Source Type: research