Analog Devices Global

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Tony Yincai Liu

Dennis A Dempsey

Hanqing Wang

Shurong Gu

GuangYang Qu

Junbiao Ding

Li Wang

John Jude O'Donnell

Jun Gao

Yimiao Zhao

Sharad Vijaykumar

Leicheng Chen

Junbiao s/O Ding

John Jude O'DONNELL

The present disclosure provides a current-to-voltage signal converter which may operate at an adjusted voltage. The current-to-voltage converter includes a trans-impedance amplifier which converts a current input into a voltage output. The voltage output may operate around an undesirable predetermined voltage, and must therefore be adjusted in order to make it suitable for any downstream signal processing circuitry, such as an ADC. As such, a subtractor circuit is coupled to the output of the trans-impedance amplifier. At the input of the subtractor circuit, a voltage adjustment circuit is employed, to adjust the voltage input to the subtractor circuit. As such, the input to the subtractor is adjusted between a first predetermined voltage threshold and a second predetermined voltage threshold, and the subtractor circuit may therefore be a low-voltage component.

Current-to-voltage signal converter

This disclosure describes techniques for selecting one of a plurality of modes in which to operate an amplifier. The techniques include configuring input routing circuitry, coupled to first and second inputs of the amplifier, based on the selected one of the plurality of modes; selectively applying a resistance to an output of the amplifier, using feedback routing circuitry, based on the selected one of the plurality of modes; and selectively applying one of a plurality of reference voltages, using reference voltage routing circuitry, coupled to the first and the second inputs of the amplifier, based on the selected one of the plurality of modes.

Amplifier configurable into multiple modes

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

Embodiments of the disclosure can provide digital-to-analog converter (DAC) termination circuits. A single or multiple parallel impedance networks can be coupled to a DAC to reduce the DAC's AC impedance, increase the DAC speed, and reduce the DAC settling time. The parallel impedance networks can be coupled to one or more of the DAC terminals in termination specific cases, or to nodes within the DAC. In an example, one-sided T-termination can be used with a single termination impedance path coupled in parallel with the DAC terminals, for reducing AC impedance at the DAC reference terminals, increasing speed, and reducing settling time. In an example, multiple impedance networks can be used in an H-bridge termination solution, which can be useful for high resolution DACs with or within a high voltage range.

Digital-to-analog converter (DAC) termination

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.

Impedance characteristic circuit for electrochemical sensor

A multiple output, multiple impedance string digital-to-analog converter (DAC) circuit can provide a first output having a first resolution in response to a first digital input signal and a second output having a second resolution in response to a second digital input signal. A main impedance string and a secondary impedance string can be coupled using switching networks to provide a first DAC output. By coupling additional switches to the main impedance string and by sharing the main impedance string, a second DAC output can be realized.

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Beijing, China

Tony Yincai Liu