Flash analog-to-digital converter using resonant-tunnelingmultiple-valued circuits

摘要

We have proposed a flash analog-to-digital converter (ADC) thatuses resonant-tunneling complex gates not only as ternary quantizers butalso as ternary-to-binary encoder circuits. The ternary quantizers,consisting of monostable-to-multistable transition logic (MML) circuits,convert the analog input signal into the ternary thermometer code. Thiscode is then converted into the binary Gray-code output by amultiple-valued, multiple-input monostable-to-bistable transition logicelement (M²-MOBILE). By assuming InP-based resonant-tunnelingdiodes and heterojunction field-effect transistors, we have carried outSPICE simulation that demonstrates ultrahigh-speed ADC operation at aclock frequency of 5 GHz. Compact circuit configuration, which is due tothe combination of MML and M²-MOBILE, reduces the devicecount and power dissipation by a factor of two compared with previousRTD-based ADCs