A family of logic circuits, called
gated diode logic circuits, is disclosed wherein
small amplitude signals, typically a fraction of the supply
voltage, can be sensed and amplified by applying a
small amplitude signal to a gate of a
gated diode in a sampling mode and changing a
voltage of a source of the
gated diode in an evaluation mode. One or more isolation devices may be connected between each
small amplitude signal and a gate of the gated
diode, wherein the isolation device passes the small amplitude
signal to the gate of the gated
diode in the sampling mode, and isolates the small amplitude signal from the gate in the evaluation mode for amplification and performing fast logic operations (logic functions). The disclosed gated
diode logic circuits overcome the Vt variation problem in FETs by detecting and amplifying the small logic signals utilizing gated diodes that have relatively low Vt variation. The amplified signals may then be processed by conventional logic circuits to perform certain logic functions in a gated diode logic circuit. The Vt variation of the gated diode is relatively small compared to the small logic signal amplitude and can be controlled relatively precisely. Typically, Vt of the gated diode can be set to a fraction of the small logic signal amplitude. Thus, in a gated diode logic circuit, the gated diode circuit can sense and amplify the small logic signals sufficiently to perform the various logic operations in conjunction with conventional logic circuits. The output(s) of the gated diode logic circuit can be of a standard full
CMOS voltage swing, or can be scaled down in amplitude and further processed by other gated diode logic circuits.