1. A circuit comprising: a sense amplifier circuit which operates in response to a V.sub.CC supply voltage, the sense amplifier circuit having an associated bias current; and a bias circuit coupled to the sense amplifier circuit, the bias circuit controlling the bias current to maintain an operating speed of the sense amplifier circuit when the V.sub.CC supply voltage decreases, and when the temperature of the circuit increases, wherein the bias circuit comprises circuitry for controlling a logic low voltage provided by the sense amplifier circuit to be less than a predetermined threshold value.