A double chopper-stabilized analog front-end （DCS-AFE） circuit for a thermopile sensor is presented, which includes a closed-loop front-end amplifier and a 2nd-order 1 bit quantization sigma-delta modulator. The amp...A double chopper-stabilized analog front-end （DCS-AFE） circuit for a thermopile sensor is presented, which includes a closed-loop front-end amplifier and a 2nd-order 1 bit quantization sigma-delta modulator. The amplifier with a closed-loop structure ensures the gain stability against the temperature. Moreover, by adopting the chopper-stabilized technique both for the amplifier and 2nd-order 1-bit quantization sigma-delta modulator, the low-frequency 1/f noise and offset is reduced and high resolution is achieved. The AFE is implemented in the SMIC 0.18 μm 1P6M CMOS process. The measurement results show that in a 3.3 V power supply, 1 Hz input frequency and 3KHz clock frequency, the peak signal-to-noise and distortion ratio （SNDR） is 55.4 dB, the effective number of bits （ENOB） is 8.92 bit, and in the range of -20 to 85 degrees, the detection resolution is 0.2 degree.展开更多
This paper presents a low noise complimentary metal-oxide-semiconductor（CMOS） detection chip for amperometric electrochemical sensors.In order to effectively remove the input offset of the cascaded integrators and t...This paper presents a low noise complimentary metal-oxide-semiconductor（CMOS） detection chip for amperometric electrochemical sensors.In order to effectively remove the input offset of the cascaded integrators and the low frequency noise in the modulator,a novel offset cancellation chopping scheme was proposed in the Incremental AS analog to digital converter（IADC）.A novel low power potentiostat was employed in this chip to provide the biasing voltage for the sensor while mirroring the sensor current out for detection.The chip communicates with FPGA through standard built in I2 C interface and SPI bus.Fabricated in 0.18-μm CMOS process,this chip detects current signal with high accuracy and high linearity.A prototype microsystem was produced to verify the detection chip performance with current input as well as micro-sensors.展开更多
基金supported by the Research on Information Technology of a New Generation of Strategic Leading Scientific and Technological Special System(No.XDA06020401)
文摘A double chopper-stabilized analog front-end （DCS-AFE） circuit for a thermopile sensor is presented, which includes a closed-loop front-end amplifier and a 2nd-order 1 bit quantization sigma-delta modulator. The amplifier with a closed-loop structure ensures the gain stability against the temperature. Moreover, by adopting the chopper-stabilized technique both for the amplifier and 2nd-order 1-bit quantization sigma-delta modulator, the low-frequency 1/f noise and offset is reduced and high resolution is achieved. The AFE is implemented in the SMIC 0.18 μm 1P6M CMOS process. The measurement results show that in a 3.3 V power supply, 1 Hz input frequency and 3KHz clock frequency, the peak signal-to-noise and distortion ratio （SNDR） is 55.4 dB, the effective number of bits （ENOB） is 8.92 bit, and in the range of -20 to 85 degrees, the detection resolution is 0.2 degree.
基金supported by the State Key Development Program for Basic Research of China(No.2015CB352100)
文摘This paper presents a low noise complimentary metal-oxide-semiconductor（CMOS） detection chip for amperometric electrochemical sensors.In order to effectively remove the input offset of the cascaded integrators and the low frequency noise in the modulator,a novel offset cancellation chopping scheme was proposed in the Incremental AS analog to digital converter（IADC）.A novel low power potentiostat was employed in this chip to provide the biasing voltage for the sensor while mirroring the sensor current out for detection.The chip communicates with FPGA through standard built in I2 C interface and SPI bus.Fabricated in 0.18-μm CMOS process,this chip detects current signal with high accuracy and high linearity.A prototype microsystem was produced to verify the detection chip performance with current input as well as micro-sensors.
