There are a number of circuits and techniques for implementing minimum and maximum functions. One example, as seen in FIG. 1, uses a pair of operational amplifiers OA1, and OA2. As seen therein, the circuit receives input signals X1 and X2, both in the form of voltages, and produces output signal Y, a voltage that satisfies the function:Y=min(X1, X2) 
This prior art circuit uses voltages rather than currents as its signals. This has the disadvantage of not interfacing to current-mode circuitry, such as Gilbert translinear circuits, without the addition of resistors. The op-amps are large, and consume significant amounts of current. The present invention comprises an improved circuit to implement the minimum function. It uses currents for both its input and output variables. The circuit is small and uses minimal current beyond that required to represent its input quantities.
USPTO Backgrounds
USPTO Backgrounds