A Resistor/Transconductor Network for Linear Fitting

We present a continuous time analog VLSI CMOS circuit consisting of resistors and transconductors for computing the best-fit line to a set of data points. The circuit can implement standard least-squares linear fitting, as well as a form of linear fitting that is more robust to outliers. We analyze the static and transient response of the chip, and present design criteria given desired constraints on speed and accuracy. Finally, we describe the transistor level design and measurement results from a 50-input prototype fabricated using a 1.2 mu m n-well process.