Function generator to study the dielectric breakdown in thin film structures

Characterization of breakdown in thin films requires testing experimental samples with different voltage patterns in order to obtain dielectric parameters, e.g. breakdown voltage and charge to breakdown. The most common voltage patterns used are voltage ramp and step. This paper describes design and implementation of a function generator especially suited for thin films testing. The generator can be controlled using a computer, performing many different voltage patterns. This feature makes it a very versatile instrument, useful in a wide range of experiments. The system is based on a switching DC power supply (flyback converter), controlled by a computer (on-board microcontroller). The control system is a PD with a feedforward loop.