A GaAs 4K BIT Static Ram with Noemally-on and -OFF Combination Circuit

A 4096 × 1bit GaAs static RAM with normally-on and -off combination circuit configuration was designed and fabricated. In the design phase, power/speed trade-off was carefully considered. Transfer gates of memory cells, column switches, word line drivers, address buffers and a sense amplifier were constructed using normally-on type circuit to speed up operation, while other parts, such as flip-flops in memory cells and decoder circuits, were realized by normally-off type circuit to save power. The memory cell size was 48um × 67um, and the chip size was 4.40mm × 5.05mm. The measured X-address access time was 2.6 nsec at power dissipation of 1.8 W.