CMOS current mode logic circuits using subthreshold conduction for low power operation

摘要

The switching transistors in a low-power CMOS current-mode logic circuit are biased to operate in weak inversion. The current-switching structure reduces noise and sensitivity to the process, voltage and temperature (PVT) variations which affect conventional subthreshold CMOS logic circuits. In retinal or cochlear implants analogue circuits operate in weak inversion to achieve low power, and by using current-mode logic satisfactory mixed analogue and digital low-power integrated circuits can be implemented. The logic swing is low and the data rate can be high. The current source Q1 operates in saturated weak inversion. The symmetry of the current-steering branches reduces input pattern sensitivity. A full adder is illustrated.