Hybrid Pass Transistor Logic With Ambipolar Transistors

The pass transistor logic (PTL) family enables compact circuits to reduce area and power consumption, but inter-stage inverters are required for signal integrity and complementary signals. Similarly, dual-gate ambipolar field-effect transistors are exceptionally logically expressive and provide a single-transistor XNOR operation, but numerous inverters are required to provide complementary signals. In both cases, these inverters and complementary signals significantly degrade overall system efficiency. Ambipolar field-effect transistors are a natural match for PTL, and we therefore propose a new hybrid ambipolar-PTL logic family that exploits the compact logic of PTL and the ambipolar capabilities of ambipolar field-effect transistors. This logic family is a hybrid between PTL and static CMOS-like logic that is made efficient by the use of ambipolar transistors. Novel hybrid ambipolar-PTL circuits were designed and simulated in SPICE, demonstrating strong signal integrity along with the efficiency advantages of using the required inverters to simultaneously satisfy the requirements of PTL and ambipolar circuits. In comparison to the ambipolar field-effect transistors in the conventional static CMOS logic structure, the proposed ambipolar-PTL family can reduce propagation delay by 33%, energy consumption by 88%, energy-delay product by a factor of 10, and area-energy-delay product by a factor greater than 20.