BiCMOS circuit technology for high-speed DRAMs

A BiCMOS circuit technology featured by a novel bit-line sense amplifier has been developed. The bit-line sense amplifier is composed of a BiCMOS differential amplifier, the impedance-converting means featured by the CMOS current mirror circuit or the clocked CMOS inverter between the bit line and the base node of the BiCMOS differential amplifier, and a conventional CMOS flip-flop. This technology can reduce the access time to half that of a conventional CMOS DRAM access time. Applied to a 1-kb DRAM test chip, a new BiCMOS circuit technology was successfully verified. Furthermore, the sensitivity and area penalty of the new BiCMOS bit-line sense amplifier and future applications to megabit DRAMs are discussed.>