Semiconductor devices in switching mode. Static and dynamic characteristics of ideal and real logic circuits. The realization of logic circuits with transistors. CMOS, ECL, TTL, BiCMOS, logic circuits. Analysis of static and dynamic characteristics of real logic circuits from a user perspective. Comparators and the Schmitt circuit. Bistable, monostable circuits, relaxation oscillators. Astable generators of linear temporal databases. Applying to generation of clock signals, time-out logic, watch-dog timer, microprocessor supervisory circuits. ROM memory. RAM memory. Programmable components. A/D and D/A converters. Discretization per amplitude and time. Implementation of the converter. Connecting to the processor bus. An optical encoder as a A/D converter for position and velocity. Pulse-width modulation as D/A conversion. Use of converters. An example of digital to physical conversion by means of a stepper motor. Examples of digital systems. Power in the digital system. Galvanic isolation. Optocouplers.