Abstract: Broadly speaking, embodiments of the present techniques provide a voltage monitoring circuit for low power minimum-energy sensor nodes. The circuit comprises sensing circuitry to sense a monitored signal having a plurality of operating signal states; a first comparator having a first input for receiving an upper threshold signal; and a second comparator having a first input for receiving a lower threshold signal, the upper and lower threshold signals defining a range which includes at least one signal state of the plurality of operating states of the monitored signal, wherein the first and second comparators have a bias input for receiving a bias configuration setting, the bias configuration setting being selectable according to an operating signal state of the monitored signal.

Abstract: Disclosed herein is a demodulator, including: a splitting/matching section for carrying out a matching process of making the amplitude and phase of a first modulated signal match respectively the amplitude and phase of a second modulated signal; and a demodulation section for generating a demodulated signal on the basis of the first modulated signal and the second modulated signal, which have been subjected to the matching process carried out by the splitting/matching section, wherein the splitting/matching section has a splitting section, a first matching section, and a second matching section, the first circuit-element constants determining the first input impedance of the first matching section and the second circuit-element constants determining the second input impedance of the second matching section are set at values determined in advance in order to make the first input impedance equal to the second input impedance.

Abstract: A demodulation circuit for an Amplitude Shift Keyed (ASK) modulated signal includes an envelope detector, an alternating voltage amplifier, a differentiator circuit, and a comparator having a hysteresis connected in series. The envelope detector produces an envelope signal from the received ASK signal. The amplifier blocks the DC component of the envelope signal and amplifies AC components of the envelope signal to obtain a steeper slope of the rising and falling edges. The differentiator circuit then processes the transition edges to provide a differentiated signal having positive and negative electrical pulses. The comparator converts the pulses into a binary data stream which corresponds to the transmitted data stream. The combination of the differentiated signal and comparator having a hysteresis enables better stability and sensitivity of the ASK demodulation circuit.

Abstract: A semiconductor device is provided, which comprises a first demodulation circuit, a second demodulation circuit, a first bias circuit, a second bias circuit, a comparator, an analog buffer circuit, and a pulse detection circuit. An input portion of the pulse detection circuit is electrically connected to an output portion of the analog buffer circuit, a first output portion of the pulse detection circuit is electrically connected to an input portion of the first bias circuit, and a second output portion of the pulse detection circuit is electrically connected to an input portion of the second bias circuit.

Abstract: An RFID reader device (31), of the type comprising a demodulator (6) for receiving from a RFID tag (11) an AM (Amplitude Modulation) wave (20) having a predetermined frequency (f) and for retrieving, from the AM wave (20), a demodulated output (6a) associated to predetermined positive or negative Amplitudes of said AM wave (20), said demodulated output having a portion with a frequency F. The AM demodulation system comprises at least a second demodulator (26) for receiving the AM wave (20) and retrieving a second demodulated output (26a) associated to Amplitudes opposite to the predetermined positive or negative Amplitudes, said second demodulated output having a portion with said frequency F; the RFID reader includes a block (27) having, in input, the demodulated output (6a) and the second demodulated output (26a) and returning, in output, an enforced demodulated output (30) with a portion with frequency (f1) doubled with respect to said frequency (F).

Abstract: An adaptive demodulator for a contactless device, including a rectifier configured to rectify a voltage which is dependent on a signal received by the contactless device, and a voltage regulator coupled to the rectifier and configured to adjust the voltage to be within a voltage window.

Abstract: AM (Amplitude Modulation) demodulation system (36) for an RFID reader device (31), of the type comprising a demodulator (6) for receiving from a RFID tag (11) an AM (Amplitude Modulation) wave (20) having a predetermined frequency (f) and for retrieving, from the AM wave (20), a demodulated output (6a) associated to predetermined positive or negative Amplitudes of said AM wave (20). The AM demodulation system comprises at least a second demodulator (26) for receiving the AM wave (20) and retrieving a second demodulated output (26a) associated to Amplitudes opposite to the predetermined positive or negative Amplitudes and a block (27) having, in input, the demodulated output (6a) and the second demodulated output (26a) and returning, in output, an enforced demodulated output (30) with a frequency (f1) greater than the predetermined frequency (f).

Abstract: An envelope detector that does not generate an undesirable DC offset at its DC output signal. An envelope detector according to the present teachings includes a circuit for performing a DC level shift on an AC input signal applied to the envelope detector such that a magnitude of the DC level shift is proportional to a peak envelope of the AC input signal.

Abstract: A detector comprises a first diode for detecting a high-frequency signal applied to the detector, a bias unit for supplying a predetermined bias voltage to the first diode; a first resistor having an end connected to the bias unit and another end connected to the first diode, a second diode connected in series with the first diode and having a same characteristic as the first diode, a second resistor having an end connected to the second diode and another end connected to a ground, and a detected voltage output terminal directly connected to a junction between the first diode and the second diode. The sum of a detected voltage generated by the first diode and a DC offset voltage caused by the bias voltage appears at the detected voltage output terminal. The first resistor has a resistance value different from that of the second resistor, and those resistance values are set to compensate for variations in the detected voltage with temperature.

Abstract: A demodulator circuit for demodulating a signal ASK-modulated with modulation pulses equal in duration, and having a small depth of modulation and large dynamic range comprises an amplitude limiter (10) through which an amplitude-dependent current flows when the amplitude of the signal to be demodulated exceeds its limiting threshold value. Furthermore comprised is an envelope detector (12) to the input of which the signal to be demodulated is applied, as well as a differentiating network (14) configured so that it differentiates the output signal of the envelope detector (12) and outputs a signal pulse only when the change in amplitude of this output signal is in one direction. A bandpass filter (18) in the demodulator circuit passes, from a signal derived from an amplitude-dependent current from the amplitude limiter (10), the frequency component attributed to the duration of the modulation pulses.

Abstract: A diode device with a low or negligible threshold voltage includes at least one field effect transistor, the gate of the field effect transistor being connected to the drain of the field effect transistor. The threshold voltage of the diode device is approximately of the same magnitude as the potential of the gate of the field effect transistor forming part of the diode device.