A 16bit sigma-delta audio analog-to-digital converter is developed.It consists of an analog modulator and a digital decimator.A standard 2-order single-loop architecture is employed in the modulator.Chopper stabilizat...A 16bit sigma-delta audio analog-to-digital converter is developed.It consists of an analog modulator and a digital decimator.A standard 2-order single-loop architecture is employed in the modulator.Chopper stabilization is applied to the first integrator to eliminate the 1/f noise.A low-power,area-efficient decimator is used,which includes a poly-phase comb-filter and a wave-digital-filter.The converter achieves a 92dB dynamic range over the 96kHz audio band.This single chip occupies 2.68mm2 in a 0.18μm six-metal CMOS process and dissipates only 15.5mW power.展开更多
Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overl...Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overload protection and multi-motor power equilibrium. But its theory when used in large power fan and pump could not meet the needs of belt conveyor soft-start operation. Focusing on the theo- retical analysis of the lubrication oil flow needed by the transmission procedure to form the oil-film. Put forward concrete calculation methods of lubrication flow and how to de- cide number of oil-films used in belt conveyor.展开更多
Rotor chopper control is a simple and effective drive method for induction motor. This paper presents a novel IGBT chopper topology,which can both adjust rotor resistance and protect IGBT efficiently. Investigation on...Rotor chopper control is a simple and effective drive method for induction motor. This paper presents a novel IGBT chopper topology,which can both adjust rotor resistance and protect IGBT efficiently. Investigation on the quasi transient state of the rotor rectifying circuit is made, and a nonlinear mapping between the equivalent resistance and the duty cycle is deduced. Furthermore, the method for determining the magnitude of the external resistor is introduced.展开更多
This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS microphone.The IoT device consists of an M&NEMS resistive accelerometer associated with an electron...This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS microphone.The IoT device consists of an M&NEMS resistive accelerometer associated with an electronic readout circuit,which is a silicon nanowire and a Continuous-Time(CT)△∑ADC.The first integrator of the△∑ADC is based on a positive feedback DC-gain enhancement two-stage amplifier due to its high linearity and low-noise operations.To mitigate both the offset and 1/f noise,a suggested delay-time chopper negative-R stabilization technique is applied around the first integrator.A 65-nm CMOS process implements the CT△∑ADC.The supply voltage of the CMOS circuit is 1.2-V while 0.96-mW is the power consumption and 0.1-mm^(2) is the silicon area.The M&NEMS microphone and△∑ADC complete circuit are fabricated and measured.Over a working frequency bandwidth of 20-kHz,the measurement results of the proposed IoT system reach a signal to noise ratio(SNR)of 102.8-dB.Moreover,it has a measured dynamic range(DR)of 108-dB and a measured signal to noise and distortion ratio(SNDR)of 101.3-dB.展开更多
文摘A 16bit sigma-delta audio analog-to-digital converter is developed.It consists of an analog modulator and a digital decimator.A standard 2-order single-loop architecture is employed in the modulator.Chopper stabilization is applied to the first integrator to eliminate the 1/f noise.A low-power,area-efficient decimator is used,which includes a poly-phase comb-filter and a wave-digital-filter.The converter achieves a 92dB dynamic range over the 96kHz audio band.This single chip occupies 2.68mm2 in a 0.18μm six-metal CMOS process and dissipates only 15.5mW power.
文摘Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overload protection and multi-motor power equilibrium. But its theory when used in large power fan and pump could not meet the needs of belt conveyor soft-start operation. Focusing on the theo- retical analysis of the lubrication oil flow needed by the transmission procedure to form the oil-film. Put forward concrete calculation methods of lubrication flow and how to de- cide number of oil-films used in belt conveyor.
文摘Rotor chopper control is a simple and effective drive method for induction motor. This paper presents a novel IGBT chopper topology,which can both adjust rotor resistance and protect IGBT efficiently. Investigation on the quasi transient state of the rotor rectifying circuit is made, and a nonlinear mapping between the equivalent resistance and the duty cycle is deduced. Furthermore, the method for determining the magnitude of the external resistor is introduced.
文摘This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS microphone.The IoT device consists of an M&NEMS resistive accelerometer associated with an electronic readout circuit,which is a silicon nanowire and a Continuous-Time(CT)△∑ADC.The first integrator of the△∑ADC is based on a positive feedback DC-gain enhancement two-stage amplifier due to its high linearity and low-noise operations.To mitigate both the offset and 1/f noise,a suggested delay-time chopper negative-R stabilization technique is applied around the first integrator.A 65-nm CMOS process implements the CT△∑ADC.The supply voltage of the CMOS circuit is 1.2-V while 0.96-mW is the power consumption and 0.1-mm^(2) is the silicon area.The M&NEMS microphone and△∑ADC complete circuit are fabricated and measured.Over a working frequency bandwidth of 20-kHz,the measurement results of the proposed IoT system reach a signal to noise ratio(SNR)of 102.8-dB.Moreover,it has a measured dynamic range(DR)of 108-dB and a measured signal to noise and distortion ratio(SNDR)of 101.3-dB.
