Design Of CMOS Differential Voltage Current Conveyor And Its Applications

Current mode circuit has vast rang of prospects because of its advantages such asgood linearity, low power and fast slew rate etc. The second generation current conveyor(CCⅡ) is the versatile current mode building block of integrated circuit. The article mainlypresents a novel differential voltage current conveyor (DVCCⅡ) and a novel currentcontrolled differential voltage current conveyor (CCDVCCⅡ). The applications of currentconveyor include filters and instrumentation amplifier. The main researches are as follows:(1) The DVCCⅡwith exact voltage following performance and large rang of commonmode input voltage is designed. The large range of input voltage is realized by usingthe rail to rail input stage. The exact current and voltage following performance areachieved by improving current mirror. The simulate result shows that in 1.8V supplyvoltage, the common mode input voltage range is 0～1.8V. The voltage following erroris 4.4×10-6%.The current following error is 4.16×10-9%.(2) A novel differential current conveyor (DVCCⅡ) with common mode detection ispresented. The operation of wide linear range relies on biasing a long tail differentialpair with a dynamic tail current. The simulate result shows that in 1.8V supply voltage,the input voltage linear rang is×0.6V～0.59V. The voltage following error is8.32×10-3%.The current following error is 7.9×10-8%.(3) Two CCDVCCⅡs are proposed. The parasitic resistances at X-terminal can becontrolled by input bias current of the linear loop. One of the trans-linear loop consistsof two NMOS transistors and two PMOS transistors, the value of the parasiticresistance is 0.883k--2.46kΩ.Another consists of two NMOS transistors.The valueof the parasitic resistance are 0.982k--3.8kΩand-3 .8k--Ω0 .982kΩ.(4) The several applications are realized by using novel DVCCⅡand CCDVCCⅡ. Theinstrumentation amplifier is realized. The gain can be tuned by the input bias current. Ithas wide bandwidth and high common mode ratio (CMRR).The current modemultifunction filter,voltage mode multifunction filter and mix mode multifunctionfilter are realized. The functions of the filters can be selected by digital switches. Thepole frequency and quality of the filters can be tuned by bias current of theCCDVCCⅡ.