Embodiments help dynamically configure the width of PCIe links and also determine how to best configure the appropriate link width. Also described are processes, pharmaceutical compositions, pharmaceutical preparations and pharmaceutical use of the compounds in the treatment of mammals, including human for central nervous system disorders and other disorders which may affect CNS function. Various circuits and embodiments such as operational transconductance amplifiers, biasing circuits, integrators, continuous-time sigma delta modulators, track-and-bold circuits, and others are presented.