Analog Devices International Unlimited Company

Analog Devices Global

Analog Devices Global Unlimited Company

Junbiao Ding

Hanqing Wang

GuangYang Qu

Yimiao Zhao

Rengui Luo

Yincai Tony Liu

Baotian Hao

Hengfang Mei

Tony Yincai Liu

Dennis A Dempsey

John Jude O'Donnell

Shurong Gu

Leicheng Chen

An apparatus comprises an integrated circuit that includes an input to receive an electrical input signal from an electronic sensor, wherein the input signal includes a direct current (DC) offset and a varying signal component; a digital-to-analog converter (DAC) circuit configured to subtract the DC offset from the input signal; a programmable gain amplifier (PGA) operatively coupled to the DAC circuit, wherein the PGA circuit is configured to apply signal gain to the varying signal component of the input signal; and a measurement circuit configured to generate a measure of the varying signal component.

Devices and methods for smart sensor application

An apparatus comprises a load resistance connectable in series with the electronic sensor to form a series resistance of the load resistance and the internal impedance of the electronic sensor; an excitation circuit configured to apply a predetermined voltage to a circuit element; and a measurement circuit configured to: initiate applying the predetermined voltage to the series resistance and determining the series resistance; initiate applying the predetermined voltage to the load resistance and determining the load resistance; and calculate the internal impedance of the sensor using the determined series resistance and the load resistance, and provide the calculated internal impedance to a user or process.

A device and method for measuring the internal impedance of an electronic sensor uses configurable gain stages to selectively apply different excitation signals to the sensor under test in order to ensure adequate signal-to-noise ratio to provide accurate measurement of the internal impedance over a broader range of internal impedances than the prior art.

The present disclosure relates to a digital-to-analog converter (DAC) which includes a resistor string and a transfer function modification circuit. The transfer function modification circuit may be a calibration circuit for calibrating the DAC, The calibration circuit may include a plurality of current sources, which may be current DACs. Each of the current DACS inject current into, or drain current from, a respective node of the resistor string, in order to correct for voltage errors. The injected currents may be positive or negative, depending on the voltage error. The current DACs are controlled by trim codes, which are set dependent on the measured or simulated voltage errors for a given resistor string.

Digital-to-analog converter transfer function modification

A electrochemical or other sensor interface circuit architecture can deliver substantial DC offset bias to an electrochemical or other sensor separately or independently from delivering a time-varying AC excitation signal, which can then be provided with higher resolution, which, in turn, can allow better resolution of the measured response signal providing the impedance characteristic of sensor condition. For example, a differential time-varying AC excitation signal for the sensor condition characteristic can be delivered separately and independently from a differential stable (e.g., DC or other) bias signal, such as by using separate digital-to-analog converters (DACs), so that providing the more stable signal does not limit the resolution and accuracy of the time-varying signal, such as by using up the dynamic range of a single DAC.

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Shanghai, China

Junbiao Ding