Design techniques for a compatible single and dual supply analog cell library

Techniques for building an analog-cell library that can operate with a single or dual power supply without user intervention are presented. The cells have been designed to be easily incorporated into a mixed-signal VLSI system. These techniques lead to fewer cells in a given library because a single cell can operate on both a single and dual supply. Conventional approaches would typically result in twice the number of cells in order to accommodate single and dual power supplies. To demonstrate the feasibility of the single and/or dual supply concept, the cell library has been used to construct both a parallel and a serial output 10-b plus sign A/D converter. Detailed circuitry is given for the substrate voltage sensor, a TTL-compatible input stage, a general-purpose analog multiplexer (MUX), a master bias circuit, an adjustable precision bandgap reference, and an autozero circuit