A
low voltage logic circuit with asynchronous SET and / or RESET functions is described herein. The
low voltage logic circuit may be primarily used in forming
low voltage flip-flop circuits, but may also be used to form multiplexers and other logic configurations. The flip-flop circuit described herein improves upon existing low
voltage architectures by providing a flip-flop circuit, which can operate at relatively low supply voltages (e.g., less than about 1.8V), with SET and / or RESET capability. In doing so, the improved flip-flop circuit may be used within a
phase frequency detector, programmable counter, or
frequency divider of a
phase locked loop (PLL) or
delay locked loop (DLL) device. However, the improved flip-flop circuit may be used with any low
voltage circuit or device that may require, use or benefit from a SET or RESET function. In some embodiments, one or more level shift circuits may be included so that the low
voltage flip-flop circuit may receive CML, TTL and / or
CMOS logic levels (among others).