| Summary: | 碩士 === 崑山科技大學 === 電子工程研究所 === 97 === We propose a current comparator based on differential Wilson current mirrors. The Wilson Current Comparator (WCC) possesses high sensibility and performs high speed switching operations. We utilize the WCC to implement novel circuits such as current-mode sense amplifier, data converter, and current-mode logic gates. Therefore, utilizing WCC simplifies traditional circuit designs and reduces power consumptions. The WCC comprises differential current mirrors where tail current is realized by the self-biased structure of the Wilson current mirror. Since Wilson current mirror advantages very high output-resistance that stabilize output currents, the differential WCC highly sense input and perform high-speed switching operation. The current required to perform the comparing function can be easily adjusted by adequate MOS aspect ratios and in this way the power consumption is easily optimized. We illustrate sense amplifier, data converter, and current-mode logic circuits to verify WCC performance. Fabricated in 0.18?慆, the sense amplifier has sensing time 0.2 ns, the direct intermediate-frequency (IF) to digital converter only consumes 2.2mW, and the current-mode logic circuits are also proved having nearly constant power consumption with respect to frequency increase of clock signals such that this type of current mode logic circuits have the least power-delay product (PDP) performance especially for complex logic functions. According to the above examples, we’ve verified that circuits exploiting WCC structure are superior to state-of-the-art VLSI circuits utilizing conventional comparators.
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