Hybrid Dynamic MCML Style: A High Speed Dynamic MCML Style

Abstract

This paper proposes hybrid dynamic current mode logic (H-DyCML) as an alternative to existing dynamic CML (DyCML) style for digital circuit design in mixed-signal applications. H-DyCML introduces complementary pass transistors for implementation of logic functions. This allows reduction in the stacked source-coupled transistor pair levels in comparison to the existing DyCML style. The resulting reduction in transistor pair levels permits significant speed improvement. SPICE simulations using TSMC 180 nm and 90 nm CMOS technology parameters are carried out to verify the functionality and to identify their advantages. Some issues related to the compatibility of the complementary pass transistor logic have been investigated and the appropriate solutions have been proposed. The performance of the proposed H-DyCML gates is compared with the existing DyCML gates. The comparison confirms that proposed H-DyCML gates is faster than the existing DyCML gates.