A Power-Aware Chopper-Stabilized Instrumentation Amplifier for Resistive Wheatstone Bridge Sensors

Ong, G. T.; Chan, P.K.

doi:10.1109/tim.2014.2308992

Cited by 50 publications

(25 citation statements)

References 36 publications

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“…Although the differential output voltage signal of the TMR sensors (V in ) can be as small as a few millivolts, the common-mode (CM) voltage V CM depending on the application can be much larger and even vary at the range of a few volts during the operation, as shown in Figure 3 b. To accommodate this variable CM voltage, an Instrumentation Amplifier is generally used for the read-out circuit of the sensors [ 17 , 18 , 19 ]. To accurately process the millivolt-level signal of the TMR sensor, the input referred error of the current feedback instrumentation amplifier (CFIA) should be at the microvolt or nanovolt-level [ 20 , 21 , 22 , 23 , 24 ].…”

Section: Methodsmentioning

confidence: 99%

A Novel High-Precision Digital Tunneling Magnetic Resistance-Type Sensor for the Nanosatellites’ Space Application

Chen

et al. 2018

Micromachines

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Micro-electromechanical system (MEMS) magnetic sensors are widely used in the nanosatellites field. We proposed a novel high-precision miniaturized three-axis digital tunneling magnetic resistance-type (TMR) sensor. The design of the three-axis digital magnetic sensor includes a low-noise sensitive element and high-performance interface circuit. The TMR sensor element can achieve a background noise of 150 pT/Hz1/2 by the vertical modulation film at a modulation frequency of 5 kHz. The interface circuit is mainly composed of an analog front-end current feedback instrumentation amplifier (CFIA) with chopper structure and a fully differential 4th-order Sigma-Delta (ΣΔ) analog to digital converter (ADC). The low-frequency 1/f noise of the TMR magnetic sensor are reduced by the input-stage and system-stage chopper. The dynamic element matching (DEM) is applied to average out the mismatch between the input and feedback transconductor so as to improve the gain accuracy and gain drift. The digital output is achieved by a switched-capacitor ΣΔ ADC. The interface circuit is implemented by a 0.35 μm CMOS technology. The performance test of the TMR magnetic sensor system shows that: at a 5 V operating voltage, the sensor can achieve a power consumption of 120 mW, a full scale of ±1 Guass, a bias error of 0.01% full scale (FS), a nonlinearity of x-axis 0.13% FS, y-axis 0.11% FS, z-axis 0.15% FS and a noise density of x-axis 250 pT/Hz1/2 (at 1 Hz), y-axis 240 pT/Hz1/2 (at 1 Hz), z-axis 250 pT/Hz1/2 (at 1 Hz), respectively. This work has a less power consumption, a smaller size, and higher resolution than other miniaturized magnetometers by comparison.

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Section: Methodsmentioning

confidence: 99%

A Novel High-Precision Digital Tunneling Magnetic Resistance-Type Sensor for the Nanosatellites’ Space Application

Chen

et al. 2018

Micromachines

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“…The first is a voltage-to-frequency converter that converts analog signals into the frequency domain [15][16][17]. This scheme is simple in structure, but consumes considerable power and has a slow conversion rate over a wide operating range [18]. The other technique is a voltage-to-digital converter that converts analog signals into digital signals [19,20].…”

Section: Introductionmentioning

confidence: 99%

A 24.88 nV/√Hz Wheatstone Bridge Readout Integrated Circuit with Chopper-Stabilized Multipath Operational Amplifier

Han

Kim

et al. 2020

Applied Sciences

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This paper proposes a low noise readout integrated circuit (IC) with a chopper-stabilized multipath operational amplifier suitable for a Wheatstone bridge sensor. The input voltage of the readout IC changes due to a change in input resistance, and is efficiently amplified using a three-operational amplifier instrumentation amplifier (IA) structure with high input impedance and adjustable gain. Furthermore, a chopper-stabilized multipath structure is applied to the operational amplifier, and a ripple reduction loop (RRL) in the low frequency path (LFP) is employed to attenuate the ripple generated by the chopper stabilization technique. A 12-bit successive approximation register (SAR) analog-to-digital converter (ADC) is employed to convert the output voltage of the three-operational amplifier IA into digital code. The Wheatstone bridge readout IC is manufactured using a standard 0.18 µm complementary metal-oxide-semiconductor (CMOS) technology, drawing 833 µA current from a 1.8 V supply. The input range and the input referred noise are ±20 mV and 24.88 nV/ √ Hz, respectively.

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“…In this paper, the effect of input capacitance of such an interface circuit on the sensitivity performance is investigated. When chopping is applied in other types of sensors such as inductive sensors [22], bioimpedance sensors [23] and resistive bridge sensors [16,24], the parasitic capacitance and input capacitance of the amplifier can also affect performance. Notably, in such sensors, the effect of the input amplifier capacitance and of the parasitic capacitance on the sensitivity is dependent on the chopping frequency and the bridge resistance values or inductors values.…”

Section: Introductionmentioning

confidence: 99%

“…Notably, in such sensors, the effect of the input amplifier capacitance and of the parasitic capacitance on the sensitivity is dependent on the chopping frequency and the bridge resistance values or inductors values. techniques have been widely applied in recent publications to remove flicker noise and DC offsets [6,[11][12][13][14][15][16][17][18]. One or more chopping frequencies can be applied when using chopping.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Sensitivity and Power Consumption of Chopping Techniques for Integrated Capacitive Sensor Interface Circuits

Vejdani

Allidina²,

Nabki

2017

JLPEA

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Abstract:In this paper, parameters related to the sensitivity of the interface circuits for capacitive sensors are determined. Both the input referred noise and capacitance of the input transistors are important for capacitive sensitivity. Chopping is an effective technique for signal conditioning circuits because of its capability of reducing circuit noise at low frequencies. The capacitive sensitivity and power consumption of various chopping techniques including the dual chopper amplifier (DCA), single chopper amplifier (SCA) and two-stage single chopper amplifier (TCA) are extracted for different values of total gain and sensor capacitance. The minimum sensitivity for each technique will be extracted based on the gain and sensor capacitance. It will be shown that designation of the amplifier and distribution of gain in the TCA and DCA are important for sensitivity. A design procedure for chopper amplifiers that illustrates the steps required to achieve either the best or the desired sensitivity while minimizing power consumption will be presented. It will be shown that for a small sensor capacitance and large total gain, the DCA has the best sensitivity, while for a large sensor capacitance and a lower gain, the SCA is preferable. The TCA is the desired architecture for an average total gain and a large sensor capacitance. Moreover, when the power consumption is the key requirement and the maximum sensitivity is not the goal; the TCA works best due to its potential to decrease the power consumption.

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A Power-Aware Chopper-Stabilized Instrumentation Amplifier for Resistive Wheatstone Bridge Sensors

Cited by 50 publications

References 36 publications

A Novel High-Precision Digital Tunneling Magnetic Resistance-Type Sensor for the Nanosatellites’ Space Application

A Novel High-Precision Digital Tunneling Magnetic Resistance-Type Sensor for the Nanosatellites’ Space Application

A 24.88 nV/√Hz Wheatstone Bridge Readout Integrated Circuit with Chopper-Stabilized Multipath Operational Amplifier

Analysis of Sensitivity and Power Consumption of Chopping Techniques for Integrated Capacitive Sensor Interface Circuits

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