Texas Instruments Corporation

Analog Devices International Unlimited Company

Analog Devices,inc.

George Reitsma

Dongtai Liu

Andreas Koch

Evgeny Fomin

Raymond Thomas Perry

Richard Dean Henderson

Jonathan Baldwin

Kalin V Lazarov

Michael C W Coln

Joyce Marie Mullenix

Quan Wan

David James Plourde

Alfred Gomes

Karthik Pappu

Frederick Paclibon

Paul A Perrault

James Raymond Catt

A data channel includes a power constrained first channel portion to receive energy from a limited power source and a non-power constrained second channel portion to receive energy from a different power source than the first channel portion. The first channel portion includes an ADC circuit to output an ADC data sample, a first transmitter circuit configured to serially transmit data that includes ON bits and OFF bits, and logic circuitry configured to derive transmit data from the ADC data sample. The transmitter circuit uses more energy transmitting the ON bits than the OFF bits, and the derived transmit data has a reduced number of the ON bits from the ADC data sample. The second channel portion includes a first receiver circuit to receive the derived transmit data from the first transmitter circuit of the first channel portion.

Power saving encoding for isolated galvanically data transmission

A semiconductor-based stress sensor can include a bipolar transistor device with first and second collector terminals. An excitation circuit can provide an excitation signal to an emitter terminal of the bipolar transistor device, and a physical stress indicator for the semiconductor can be provided based on a relationship between signals measured at the collector terminals in response to the excitation signal. The signals can indicate a charge carrier mobility characteristic of the semiconductor, which can be used to provide an indication of physical stress. In an example, the physical stress indicator is based on a current deflection characteristic of a base region of the transistor device.

Package stress sensor

An analog-to-digital (ADC) converter system and method of using the system that can be used in low power situations. The converter can periodically or recurrently turn off a reference standard in order to conserve power and instead using a stable supply source as a reference voltage. A precise conversion for signal from the analog to the digital domain while maintaining a low quiescent current.

ADC with precision reference power saving mode

A system for processing a signal in a signal chain having decentralized embedded power management of components of the signal chain includes an input circuit to generate a measurement signal responsive to a stimulus, where the measurement signal is indicative of a characteristic of the stimulus. The system additionally includes a signal converter circuit coupled to the input circuit to convert the measurement signal to a digital signal according to a timing condition for capturing a sample of the measurement signal. The signal converter includes a control circuit to provide electrical power to the input circuit based on the timing condition and a sampling circuit to capture the sample of the measurement signal responsive to an indicator signal generated by the sensor circuit.

Signal chain with embedded power management

A position detecting system detects and responds to the movement of a target through a sensing domain area of a plane. The movement causes the amount of the target that lies within a first sensing domain area of a first sensor to change. A second sensor detects a height from the plane to a sensor for enhancing accuracy of measurements from the first sensor.

Inductive position detection

Techniques to reduce the on-time of a multi-stage ADC circuit by combining the settling time of a signal conditioning circuit, e.g., buffer circuit, and the setting time of a residue amplifier when cancelling the offset of the signal conditioning circuit. The techniques can allow the signal conditioning circuit and the residue amplifier to settle together.

Time-efficient offset cancellation for multi-stage converters

Techniques for saving operating power of an analog-to-digital converter (ADC) are provided. In an example, a circuit can include an ADC configured to provide a multiple-bit digital representation of an analog input during a first mode of operation and an output configured to provide a single bit representation of a first comparison of the analog input signal to a second analog signal during a second mode of operation. In certain examples, the circuit can include an encoder configured to provide the multiple-bit digital representation during the first mode and to power down during the second mode of operation.

Dual mode data converter

A circuit includes a first signal swapper including a first terminal coupled to a first current source, a second terminal coupled to a second current source, a third terminal coupled to a first current terminal of a first transistor, and a fourth terminal coupled to a third current terminal of a second transistor. The first signal swapper couples the first and second terminals to the third and fourth terminals responsive to a first control signal. First and second switches couple to a gate of the first transistor. The first switch receives the input oscillation signal and the second switch receives a first reference voltage. Third and fourth switches couple to a gate of the second transistor. The third switch receives the input oscillation signal and the fourth switch receives the first reference voltage. A second signal swapper couples to the first signal swapper and to the first and second transistors.

Amplitude control with signal swapping

A resonant inductive sensing system includes an active resonator target that balances losses in the target resonator. The resonant sensor includes a sensor resonator LC circuit and a resonant target including a target resonator Lt/Ct circuit characterized by a loss factor Rts and a target quality factor Qt. The sensor resonator LC circuit and the target resonator Lt/Ct circuit are configured for operation as coupled resonators. The resonant sensor includes a sensor circuit configured to drive the resonant sensor, such that the sensor resonator LC circuit projects a magnetic sensing field based on a sensor quality factor Q, and an active negative resistance circuit &#x2212;Ra coupled to the target resonator Lt/Ct circuit, and configured to substantially cancel the loss factor Rts, such that target quality factor Qt is substantially Qt=(&#x221a;[Lt/Ct]/Rts)(RaRts/[RaRts&#x2212;Lt/Ct]).

Resonant inductive sensing with active resonator target

A circuit includes a ring oscillator and a state capture register to receive a multi-bit state of the ring oscillator captured upon occurrence of an edge of input periodic signal. The circuit also includes an edge-phase detector to assert an edge detect high signal in response to a first reference clock derived from the ring oscillator being high upon occurrence of the edge of the input periodic signal and to assert an edge detect low signal in response to the first reference clock derived from the ring oscillator being low upon occurrence of the edge of the input periodic signal. A first register receives data from the state capture register upon occurrence of one of a rising or falling edge of a second clock derived from the ring oscillator.

Ring oscillator-based timer

A multi-frequency inductive sensing system can be used for spectrographic material analysis of a conductive target material (such as tissue) based on electrical impedance spectroscopy. An inductive senor can be driven with an excitation current at multiple sensor excitation frequencies (&#x3c9;) to project a time-varying magnetic field into a sensing area on the surface of the target material, inducing eddy currents within the target material. The inductive sensor can be characterized by a sensor impedance Z(&#x3c9;) as a function of the sensor excitation frequency (&#x3c9;), and the resulting induced eddy currents. Multiple sensor impedance Zs(&#x3c9;) measurements, at the multiple sensor excitation frequencies (&#x3c9;), can be determined, which represent electromagnetic properties of the target material (such as permittivity &#x3b5;, permeability &#x3bc;, and resistivity &#x3c1;), based on the induced eddy currents. The multiple sensor excitation frequencies (&#x3c9;), and corresponding multiple sensor impedance Zs(&#x3c9;) measurements, can be selected for particular target penetration depths.

Spectrographic material analysis based on inductive sensing

For inductive sensing (such as for proximity switching), differential inductance readout is based on Sense/Reference resonators implemented as LC-ring oscillators, with L/Linductor coils and a shared (time-multiplexed) resonator capacitor. The ring oscillators include matched Lsense/Lref drivers time-multiplexed (by out enable signals), to provide Lsense/Lref resonator excitation signals to the Lsense/Lref resonators, based on resulting Lsense/Lref resonance measurements (such as of resonance state) acquired by the ring oscillators from the Lsense/Lref resonators. Differential readout data is based on the time-multiplexed Lsense/Lref resonance measurements, corresponding respectively to L/Lcoil inductances (such as based on Lsense/Lref resonator oscillation frequency). The ring oscillators can be implemented with a Schmitt trigger, converting analog resonance measurements into digital input to the Lsense/Lref drivers. Driver matching and layout matching can be used to improve accuracy. Effects of parasitic capacitance at the driver outputs can be suppressed by shorting or bootstrapping across the inactive L/Lcoil inductances.

Inductive sensing with differential inductance readout

A resonant impedance sensing system includes a class D negative impedance stage implemented with a Class D comparator, and a loop control stage implemented with an output comparator clocked by the class D comparator, establishing a negative impedance control loop that includes the resonator as a loop filter. The negative impedance stage includes a multi-level current source (such as a current DAC) interfaced to the resonator through an H-bridge controlled by the class D comparator. Class D switching synchronizes resonator oscillation voltage (input to the class D comparator) with resonator current drive (from the multi-level current source), driving the resonator with a negative impedance that balances resonator impedance to maintain sustained oscillation. Negative impedance magnitude is controlled by the loop control stage, with the output comparator generating a multi-level loop control signal the controls drive current level based on resonator oscillation amplitude (the time-average of the multi-level drive current).

Resonant impedance sensing with a negative impedance control loop implemented with synchronized class D and output comparators

Remote inductive sensing uses a sensor resonator with a remote sense inductor coupled to a resonator capacitor through a shielded transmission line. The T-line includes a signal line and a shield return line: the sense inductor is connected at a T-line sensing end between the signal line and the shield return line, and the resonator capacitor is connected at a T-line terminal end to at least the signal line. An inductance-to-data converter (IDC) is connected at the T-line terminal end to the signal line and shield return line (set to a common mode voltage). In operation, the IDC drives oscillation signals over the signal line to the sensor resonator to sustain a resonance state, with the sense inductor projecting a magnetic sensing field, and converts changes in oscillation drive signals, representing changes in resonance state resulting from a sensed condition, into sensor data corresponding to the sensed condition.

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Redwood City, CA, United States of America

George Reitsma