High-speed cascode sensing scheme for 1.0 V contact-programming mask ROM

Abstract

This paper proposes a high-speed single end sensing scheme. A low-voltage contact-programming mask ROM was designed which utilizes a cascode sense amplifier (S/A). A dummy S/A controls the bit-line pre-charging period to operate the read S/A quickly in spite of high programmed-data-dependence of the bit-line capacitance. The word-line has branches to enhance the cell current with little increase in area. A demonstrated 4 K/spl times/8 bit ROM operates with an access time of 5.7 ns and power of 2.2 mW at 1.0 V, 100 MHz, and 25/spl deg/C.