Multiple-input translinear element networks

We describe a new class of translinear circuits that accurately embody product-of-power-law relationships in the current signal domain. We call such circuits multiple-input translinear element (MITE) networks. A MITE is a circuit element, which we defined recently that produces an output current that is exponential in a weighted sum of its input voltages. We describe intuitively the basic operation of MITE networks and provide a systematic matrix technique for analyzing the nonlinear relationships implemented by any given circuit. We also show experimental data from three MITE networks that were fabricated in a 1.2-/spl mu/m double-poly CMOS process.

I. Product-of-Power-Law Circuits

Products, quotients, and power-law relationships figure prominently in many signal- and information-processing algorithms. Consequently, analog circuits embodying such relationships are important components in the construction of analog VLSI information processing systems. In the Nonlinear Circuits Handbook from Analog Devices, we find the following clear description of a general principle by which such functions may be realized:

When compound multiplications, involving roots and powers are performed (e.g., ), each input is “logged,” multiplied by a constant. exponent of appropriate magnitude and polarity, the terms are summed and/or differenced, then the antilog is taken to convert the result back into the “world of phenomena” [1].