Texas Instruments Incorporated Deutschland, Gmbh

Texas Instruments Corporation

Frank Ohnhaeuser

Michael Reinhold

Andreas Wickmann

Mikael Badenius

Miroslav Oljaca

Martin Allinger

Konstantin Schmid

The device comprises a successive approximation register, a capacitive digital-to-analog converter comprising a plurality of capacitors, the plurality of capacitors being coupled with a first side to a common node; a comparator coupled to the common node and being adapted to make bit decisions by comparing a voltage at the common node with another voltage level, and a SAR control stage for providing a digital code representing a conversion result. The device is configured to operate in a calibration mode, where the device is configured to sample a reference voltage on a first capacitor of the plurality of capacitors by coupling one side of the first capacitor to the reference voltage, to perform a regular conversion cycle with at least those capacitors of the plurality of capacitors having lower significance than the first capacitor and to provide the conversion result of the regular conversion cycle for calibrating the first capacitor.

Electronic device and method for measuring differential non-linearity (DNL) of an SAR ADC

The modulator comprises a first and second integration stages, and a comparator, the first integration stage is fully differential having: an amplifier, sets of input sampling capacitors and feedback capacitors, and the first integration stage is configured to sample the analog input voltage on a set of input capacitors during a first portion of a clock cycle and on a set of input capacitors during a second portion of the clock cycle and to sample the feedback reference voltage on a set of feedback capacitors during the first portion of the clock cycle and on a set of feedback capacitors during the second portion of the clock cycle, and the first set of feedback capacitors and the second set of feedback capacitors are randomly selected out of the plurality of sets of feedback capacitors from cycle to cycle.

Electronic device and method for analog to digital conversion according to delta-sigma modulation using double sampling

Successive approximation register (SAR) analog-to-digital converters (ADCs) generally employ capacitive digital-to-analog converters (CDACs) to perform data conversions. In these CDACs, matching of capacitive values is important, and for conventional high resolution SAR ADCs, complex trimming or calibration procedures can be too costly. Here, however, a SAR ADC is provided that performs error correction so as to reduce the overall cost compared to conventional SAR ADCs.

Digital trimming of SAR ADCs

An electronic device is provided for analog to digital conversion using successive approximation. The device comprises a first ADC stage. The first ADC stage includes a first plurality of capacitors adapted to sample an input voltage, and adapted to be coupled to either a first reference signal level or a second reference signal level. At least one capacitor of the first plurality of capacitors is adapted to be left floating. A control stage is adapted to switch the at least one floating capacitor to the first reference signal level or the second reference signal level in response to an analog to digital conversion decision made by a second ADC stage.

SAR ADC

An apparatus for analog-to-digital conversion using successive approximation is provided, which is adapted to be supplied with a single ended supply voltage. The device includes: a first analog-to-digital conversion stage including a first set of capacitors coupled with a side at a common node and adapted to sample an input voltage and to be coupled to either a first reference voltage level or a second reference voltage level, at least one capacitor of the first set of capacitors being adapted to be left floating, a control stage being adapted to connect the at least one floating capacitor to the first reference voltage level or the second reference voltage level in response to an analog-to-digital conversion decision made by a second analog-to-digital conversion stage. The first analog-to-digital conversion stage is operable to couple the common node to a supply voltage level, in particular ground, during analog-to-digital conversion.

ADC with low-power sampling

An apparatus for analog-to-digital conversion using successive approximation is provided. There is a successive approximation register or SAR controller for providing a digital code representing a conversion result, and an integral non-linearity (INL) compensator configured to provide an INL compensation signal for reducing INL of the analog-to-digital conversion in response to the digital code.

SAR ADC and method with INL compensation

A resolver arrangement that is inexpensive and yet offers high resolution and high noise rejection includes a carrier signal generator and two processing channels each of which has an analog input connected a different one of the stator coils and a channel output. Each of the processing channels includes a sigma-delta modulator with an output that supplies a bit-stream representative of an analog input signal received from a respective stator coil. Each channel also includes a first digital filter that receives the bit-stream from the sigma-delta modulator and converts the bit-stream to intermediate digital data-words. In addition, each channel has a digital synchronous demodulator that demodulates the intermediate digital data-words in synchronism with the carrier signal providing demodulated data-words. Finally, each channel has a second digital filter that averages the demodulated data-words and supplies digital output data-words on the channel output, the carrier signal being suppressed in the output data-words.

Resolver arrangement

An integrated circuit for use with an external Hall sensor that permits to at least substantially cancel out the temperature drifts of the Hall sensor, as caused by the temperature drift of the current supplied to the Hall sensor, and the gain of the Sigma-Delta modulator. Specifically, the circuit provides an integrated circuit for use with an external Hall sensor, that has an analog input for application of a Hall voltage from the Hall sensor, a digital data output and a current output for connection to a current input of the Hall sensor. The integrated circuit comprises a Sigma-Delta modulator with an input connected to the analog input and an output connected to the digital data output. An internal reference voltage source is also included in the integrated circuit, and an internal current source is connected to the current output for the Hall sensor. The internal reference voltage source is used as a reference in the current source that determines the amount of current supplied to the Hall sensor, and is also used in the Sigma-Delta modulator as a reference that determines the input voltage range. Since the same reference voltage source is used by the current source for the Hall sensor and by the Sigma-Delta modulator, the temperature drifts of the Hall voltage and the gain of the Sigma-Delta modulator cancel each other. Other benefits are low noise and an excellent common mode rejection.

Integrated circuit for use with an external hall sensor, and hall sensor module

An analog-to-digital converter receiving an analog input signal (V ) including an offset component, and includes a switched capacitor input circuit ( ) configured to sample the analog input signal (V ) to produce and store a signal representative of the sampled input signal between a first conductor ( ) and a second conductor ( ). A conversion circuit ( ) is coupled to the first conductor ( ) and the switched capacitor input circuit ( ) to produce a digital output signal (DATA OUT). An offset correction circuit ( ) includes an output coupled to the second conductor ( ) and an input receiving a digital offset correction signal (DATA IN), the offset correction circuit ( ) including a switched capacitor correction circuit ( A) operative in response to the offset correction control signal (DATA IN) to transfer charge to/from the second conductor ( ). The conversion circuit ( ) operates in response to adjustment by the offset correction circuit ( ) of a signal conducted by the second conductor ( ) to produce the digital output signal (DATA OUT) compensated for the offset component.

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Stein, Germany

Frank Ohnhaeuser