In my thesis I designed a high precision linear voltage regulator, where the pass transistor at the output stage is in common source configuration. I present the process of completing the appointed task and the achieved results in detail.
While researching literature I got to learn the types, main and subcircuits of voltage regulators. I made the system level design and wrote the specification of the subcircuits. I got acquainted with the Cadence Virtuoso 6.1.500 integrated circuit design system, in which I created the schematics. I optimized the behavior of these circuits using DC, AC, transient, stability and Monte Carlo simulations.
The designed circuit consists of three main functional units. First is the folded cascode operational amplifier, which, acting as the error amplifier of the LDO, is responsible for the preciseness of the output voltage. Second is the bandgap reference circuit, which produces the necessary bias voltages and currents for the regulator. Third is the current limiting, which reduces the short circuit current of the output, thus protecting the circuit from malfunctions caused by overload. I designed the layout of the entire circuit, then conducted the verifications necessary for manufacturing (DRC, LVS).