A novel general-purpose low-voltage rail-to-rail CMOS （ complementary metal-oxide-semiconductor transistor ） operational amplifier （op-amp）is introduced, which obtains constant transconductance, slew rate and cons...A novel general-purpose low-voltage rail-to-rail CMOS （ complementary metal-oxide-semiconductor transistor ） operational amplifier （op-amp）is introduced, which obtains constant transconductance, slew rate and constant high gain over the entire input common mode voltage range. The proposed scheme has the potential for applications in deep submicrometer technology, as the operation of the circuit does not exclusively rely on the square-law or the linear-law of transistors. The scheme is compact and suitable for applications as VLSI cell. The rail-to- rail op-amp has been implemented in DPDM 0. 6 μm mixedsignal process. The simulations show that in the entire range of input common mode voltage, the variations in transconductance, SR and gain are 1%, 2. 3%, 1.36 dB, respectively. Based on this, the layout and tape-out are carded out. The area of layout is 0. 072 mm^2. The test results are basically consistent with the circuit simulation.展开更多
A rail-to-rail amplifier with constant transconductance,intended for audio processing,is presented.The constant transconductance is obtained by a constant current technique based on the input differential pairs operat...A rail-to-rail amplifier with constant transconductance,intended for audio processing,is presented.The constant transconductance is obtained by a constant current technique based on the input differential pairs operating in the weak inversion region.MOSFETs working in the weak inversion region have the advantages of low power and low distortion.The proposed rail-to-rail amplifier,fabricated in a standard 0.35μm CMOS process,occupies a core die area of 75×183μm2.Measured results show that the maximum power consumption is 85.37μW with a supply voltage of 3.3 V and the total harmonic distortion level is 1.2%at 2 kHz.展开更多
When the voltage of an analog input signal is equal to the supply voltage, it is difficult for a conventional successive approximation ADC to correctly convert the analog signal into digital signal. This paper introdu...When the voltage of an analog input signal is equal to the supply voltage, it is difficult for a conventional successive approximation ADC to correctly convert the analog signal into digital signal. This paper introduces an improved successive approximation ADC, which can convert the rail-to-rail input range and reduce sampling time through a track-and-hold circuit. Comparator offset cancellation and capacitor self-calibration techniques are used in this ADC. Measurement results show that the peak SNDR of this ADC reaches 72 dB and the signal effective bandwidth is up to 1.25 MHz. It consumes 1 mW in the test, and the figure of merit is 123 fJ/conversion-step.展开更多
文摘A novel general-purpose low-voltage rail-to-rail CMOS （ complementary metal-oxide-semiconductor transistor ） operational amplifier （op-amp）is introduced, which obtains constant transconductance, slew rate and constant high gain over the entire input common mode voltage range. The proposed scheme has the potential for applications in deep submicrometer technology, as the operation of the circuit does not exclusively rely on the square-law or the linear-law of transistors. The scheme is compact and suitable for applications as VLSI cell. The rail-to- rail op-amp has been implemented in DPDM 0. 6 μm mixedsignal process. The simulations show that in the entire range of input common mode voltage, the variations in transconductance, SR and gain are 1%, 2. 3%, 1.36 dB, respectively. Based on this, the layout and tape-out are carded out. The area of layout is 0. 072 mm^2. The test results are basically consistent with the circuit simulation.
基金Project supported by the Science and Technology Program of Tianjin,China(No08ZCKFGX00200)
文摘A rail-to-rail amplifier with constant transconductance,intended for audio processing,is presented.The constant transconductance is obtained by a constant current technique based on the input differential pairs operating in the weak inversion region.MOSFETs working in the weak inversion region have the advantages of low power and low distortion.The proposed rail-to-rail amplifier,fabricated in a standard 0.35μm CMOS process,occupies a core die area of 75×183μm2.Measured results show that the maximum power consumption is 85.37μW with a supply voltage of 3.3 V and the total harmonic distortion level is 1.2%at 2 kHz.
文摘When the voltage of an analog input signal is equal to the supply voltage, it is difficult for a conventional successive approximation ADC to correctly convert the analog signal into digital signal. This paper introduces an improved successive approximation ADC, which can convert the rail-to-rail input range and reduce sampling time through a track-and-hold circuit. Comparator offset cancellation and capacitor self-calibration techniques are used in this ADC. Measurement results show that the peak SNDR of this ADC reaches 72 dB and the signal effective bandwidth is up to 1.25 MHz. It consumes 1 mW in the test, and the figure of merit is 123 fJ/conversion-step.
