A circuit for generating a radio-frequency signal for a surgical device is disclosed. The circuit has a voltage regulator that supplies direct current (DC) voltage, a first MOSFET, a second MOSFET, and a MOSFET driver. The MOSFET driver receives the DC voltage supplied from the voltage regulator and has a local oscillator. The local oscillator switches the first MOSFET and the second MOSFET on and off at a frequency generated by the local oscillator. The circuit further includes a transformer connected to the first and second MOSFETs, having a center tap and a main voltage applied at the center tap, and providing an alternating current (AC) output.