A circuit configuration, in particular, a switch-mode power supply, includes a transformer device and at least one semiconductor component to provide a particularly space-saving configuration having little susceptibility to interference, and with as little stray inductance as possible. The transformer device is in the form of an electromechanical conversion device, in particular, a piezo-transformer or the like, with, in particular, at least one connection of the transformer device forming a substantially mechanically identical connection to a connection of at least one semiconductor component.