Abstract: In a general aspect, a method for transmitting data by inductive coupling can include applying, at a rate of a data-carrying signal, a plurality of bursts of a periodic signal to a tuned inductive antenna circuit. The method can also include producing, in the tuned inductive antenna circuit, an antenna signal. The antenna signal can generate a magnetic field. The method can further include delimiting an amplitude of each burst of the plurality of bursts of the periodic signal in accordance with an envelope signal having a rising edge and a falling edge. The delimiting the amplitude of each burst of the plurality of bursts of the periodic signal can include generating the plurality of bursts of the periodic signal using a set of points. The set of points can define, by discrete values, a burst of the plurality of bursts of the periodic signal.

Abstract: A communication device includes a pulse width modulator that is provided with an oscillator signal at a communication carrier frequency. The pulse width modulator input is an amplified reference voltage that is regulated by a feedback loop. A modulation control provides the data signal to be transmitted. The modulation control may either be provided to the amplifier mixed with the reference voltage or may be provided to the pulse width modulator. A power transistor receives the pulse width modulator output and generates a chip output signal. An external filter is connected at the chip output to filter the signal that is provided to the communication antenna and produce a carrier sinusoid with an amplitude proportional to the pulse width modulated by voltage regulation and by the modulating data input. The power source is connected to the external filter.

Abstract: In a general aspect, a method for transmitting data by inductive coupling can include applying, at a rate of a data-carrying signal, a plurality of bursts of a periodic signal to a tuned inductive antenna circuit. The method can also include producing, in the tuned inductive antenna circuit, an antenna signal. The antenna signal can generate a magnetic field. The method can further include delimiting an amplitude of each burst of the plurality of bursts of the periodic signal in accordance with an envelope signal having a rising edge and a falling edge. The delimiting the amplitude of each burst of the plurality of bursts of the periodic signal can include generating the plurality of bursts of the periodic signal using a set of points. The set of points can define, by discrete values, a burst of the plurality of bursts of the periodic signal.

Abstract: A communication device includes a pulse width modulator that is provided with an oscillator signal at a communication carrier frequency. The pulse width modulator input is an amplified reference voltage that is regulated by a feedback loop. A modulation control provides the data signal to be transmitted. The modulation control may either be provided to the amplifier mixed with the reference voltage or may be provided to the pulse width modulator. A power transistor receives the pulse width modulator output and generates a chip output signal. An external filter is connected at the chip output to filter the signal that is provided to the communication antenna and produce a carrier sinusoid with an amplitude proportional to the pulse width modulated by voltage regulation and by the modulating data input. The power source is connected to the external filter.

Abstract: The present disclosure relates to a Near Field Communication (NFC) reader device. The NFC reader device includes a pulse generator configured to generate a signal pulse and transceiver circuitry configured to poll for a presence of an NFC transponder using the signal pulse.

Abstract: In a general aspect, a method for transmitting data by inductive coupling can include applying, at a rate of a data-carrying signal, a plurality of bursts of a periodic signal to a tuned inductive antenna circuit. The method can further include producing, in the tuned inductive antenna circuit, an antenna signal, the antenna signal generating a magnetic field. The method can further include delimiting an amplitude of each burst of the plurality of bursts of the periodic signal in accordance with an envelope signal, the envelope signal having a rising edge and a falling edge. The delimiting can include shaping the falling edge of the envelope signal using one of a digital shaping circuit and an analog shaping circuit, such that a slope of the falling edge of the envelope signal is flattened as compared to a square envelope signal.

Abstract: In a general aspect, a method for transmitting data by inductive coupling can include applying, at a rate of a data-carrying signal, a plurality of bursts of a periodic signal to a tuned inductive antenna circuit. The method can further include producing, in the tuned inductive antenna circuit, an antenna signal, the antenna signal generating a magnetic field. The method can further include delimiting an amplitude of each burst of the plurality of bursts of the periodic signal in accordance with an envelope signal, the envelope signal having a rising edge and a falling edge. The delimiting can include shaping the falling edge of the envelope signal using one of a digital shaping circuit and an analog shaping circuit, such that a slope of the falling edge of the envelope signal is flattened as compared to a square envelope signal.

Abstract: An over-current protection circuit shuts off current to an optical transmitter, such as a laser diode, if a detected current to the optical transmitter exceeds a threshold. A circuit element functions to both detect the current and switch off the current if the detected current exceeds a threshold. The circuit element may be a PMOS transistor.

Abstract: Memory sense amplifier unit for amplifying a data signal read from a memory via bit lines (2, 3), having a precharge circuit (4) comprising PMOS transistors (5, 6) and serving for rapidly precharging the bit lines (2, 3) to a supply voltage potential (VDD) of the sense amplifier unit (1); a first amplifier stage (43) comprising feedback NMOS transistors (21, 22, 24, 26) and serving for voltage level shifting and for amplifying the data signal present on the bit lines (2, 3); and having a second amplifier stage (66) for amplifying further the signal output by the first amplifier stage (43), in which case the first amplifier stage (43) can be initialized to the supply voltage potential (VDD) and the second amplifier stage (43) can be initialized to ground potential (VSS).

Abstract: Memory sense amplifier unit for amplifying a data signal read from a memory via bit lines (2, 3), having a precharge circuit (4) comprising PMOS transistors (5, 6) and serving for rapidly precharging the bit lines (2, 3) to a supply voltage potential (VDD) of the sense amplifier unit (1); a first amplifier stage (43) comprising feedback NMOS transistors (21, 22, 24, 26) and serving for voltage level shifting and for amplifying the data signal present on the bit lines (2, 3); and having a second amplifier stage (66) for amplifying further the signal output by the first amplifier stage (43), in which case the first amplifier stage (43) can be initialized to the supply voltage potential (VDD) and the second amplifier stage (43) can be initialized to ground potential (VSS).

Abstract: A circuit arrangement and method for testing the differential non-linearity (DNL) of a digital-to-analog converter (DAC) determines whether the digital-to-analog converter has an analog output that is monotonic, and thus the DAC is functional The design is appropriate for being implemented on an integrated circuit containing a digital-to-analog converter, creating an efficient self-test circuit arrangement. A counter generates a monotonic sequence of digital input codes for a digital input of the digital-to-analog converter. A monotonicity comparator, such as a one-stage or multistage sample and hold circuit arrangement, detects any non-monotonic transition in the analog output of the digital-to-analog converter, generating an error signal as an output. An output switch, such as a digital flip-flop, may be set by the error signal, for monitoring by other devices. A clock signal synchronizes the counter and the monotonicity comparator.

Abstract: The present invention encompasses techniques for reducing digital noise in integrated circuits and circuit assemblies, particularly dense mixed-signal integrated circuits, based upon shaping the noise from the digital circuit and concentrating it in a single, or a small number, of parts of the frequency spectrum. Generally, the presence of noise in the analog circuit is less important at certain frequencies, and therefore the spectral peak or peaks from the digital circuit can be carefully placed to result in little or no interference. As an example, a radio receiver might be designed such that the peaks of the digital noise lie between received channels, outside the band edges of each.

Abstract: A tuning circuit for tuning an integrated circuit filter, such as a continuous-time MOSFET-C filter, is disclosed. The tuning circuit includes a switched-capacitor network having a capacitor which matches the capacitor used in the filter to be tuned. Also included is a transistor which matches the transistor used in the filter. The switched-capacitor network has a effective resistance which is a function of the switching rate of the network. Feedback circuitry is included which produces a control signal used to vary the small signal resistance of the transistor to match the effective resistance of the switched-capacitor network. The filter is tuned by varying the rate of which the switched capacitor network is clocked thereby changing to effective network resistance. The control voltage responds by forcing the transistor resistance to match the new effective resistance of the switched-capacitor network.

Abstract: A solution to the problem of analog decision making in a "mixed-signal" integrated circuit removes pulses of the local clock from the analog decision trigger whenever chip select is active, thereby freezing the mixed-signal circuit while it is accessed.

Abstract: A switched capacitor amplifier circuit using a pair of switched capacitors to replace each resistor element of an inverting operational amplifier circuit, with the capacitors operating on opposite halves of the switching cycle to provide reduced sampling distortion.