Abstract: There is described an integrating circuit for converting light energy produced by a photodetector into a voltage signal, this integrating circuit comprising an amplifier having an input coupled to a terminal of the photodetector and an output for outputting the voltage signal, and an integration capacitor having a first electrode connected to the amplifier input and a second electrode connected to the amplifier output. The first electrode of the capacitor is formed by the terminal of the photodetector connected to the amplifier input and the second electrode is formed by a layer of conductive material deposited on top of the photodetector and separated from this photodetector by a layer of insulating material, these layers of conductive material and of insulating material being transparent or nearly transparent at least for a given range of wavelengths of light. There is also described a method of forming the integration capacitor as well as a photodetector including the integration capacitor.

Abstract: There is described an optical sensing device, a method for controlling operation of an optical sensing device comprising a light source for illuminating a surface portion with radiation, a photodetector device having at least one photosensitive element responsive to radiation reflected from the illuminated surface portion, and conversion means for integrating an output signal of said at least one photosensitive element over time during an integration period of variable duration, which duration depends on power of the light source and level of radiation reflected from the illuminated surface portion. The optical sensing device further comprises a regulating system for controlling power if the light source as a function of a comparison between a parameter representative of the evolution of the integration of the output signal of the said at least one photosensitive element and at least one reference value.

Abstract: This method uses a tester (T) capable of being connected to an integrated circuit (CI) to be tested. A random number (RNG-C) is generated and ciphered using a key (k) by a cipher algorithm to obtain a password (Gk(RNG)-C). The random number (RNG-C) is sent to the tester (T) in which the received random number (RNG-C) is ciphered using the same key (k) by a same cipher algorithm to generate therein a second password (Gk(RNG)-T). This latter is sent to the integrated circuit (CI) to be compared to the first password (Gk(RNG)-C). The test of the confidential parts (1) of the circuit is only authorised if the two passwords exhibit the required match.

Abstract: An electronic device including an electronic circuit (1, 8) for delivering an output signal (CKS) and a programmable non volatile memory (30) coupled to the electronic circuit to allow storage of a binary word (EED[7:0]) representative of at least one adjustable feature (C1, C2) of the electronic circuit (1, 8), this electronic device including at least first and second supply terminals (PAD_VDD, PAD_VSS), to which first and second supply voltages are applied (VDD, VSS) and at least one output terminal (PAD_OUT) at which the output signal from the electronic circuit is delivered. Circuits are provided for switching the output terminal into a so-called high impedance state so as to allow the introduction, in serial form, via this output terminal, of data bits intended, in particular, to be stored in the non volatile memory of the device. This device is applied, in particular, for adjusting the features of an oscillator circuit.

Abstract: The invention relates to a method for keyless unlocking of an access door to a closed space, in particular a motor vehicle, which is carried out by an electronic system, comprising a control module for an electronic lock, associated with the door and a portable transponder for authorised users. The method comprises sending an interrogation signal at low frequency from the control module to the transponders and also the exchange of data at high frequency. The control module has reception device for the above which are at least continuously in a listening mode. The method is characterised in that the low frequency transmitters are inactive in a preliminary functional mode, the high frequency transmission device in the transponder periodically emits an activation signal for said the transmission device in order that the above are only activated during limited periods, which ensures the reception of an interrogation signal for a transponder entering the low frequency communication region.

Abstract: The present invention concerns a method for filtering signals (VIN) generated by a piezo-electric type accelerometer (34) in response to detection of a shock applied to an object to which the accelerometer is connected, this method being characterised in that it is ensured, during a first step, that the signal (VIN) generated by the accelerometer (34), after having increased and exceeded a first threshold value (VTH,ON) decreases and becomes lower than a second threshold value (VTH,OFF) lower than the first threshold value (VTH,ON) after a period of time (TP,ON) greater than a minimum period of time (TP,ON,MIN) and less than a maximum period of time (TP,ON,MAX). The invention also concerns a device for filtering the signals generated by an accelerometer in response to detection of a shock applied to an object to which the accelerometer is connected. Finally, the invention concerns a portable object such as a wristwatch including a detection device of this kind.

Abstract: An electronic system with semiconductor components allows electronic circuits with conventional semiconductor components to be used, having minimal supply voltages to guarantee stable operation, lowering said minimum supply voltages. The range of supply voltages of such a circuit for which operation is stable can be extended towards low values by the effect of mutual compensation of the respective behaviors of said semiconductor components in their respective transition regions.

Abstract: There is disclosed a multi-application transponder circuit for a contactless electronic identification and/or access system including, in particular, a non-volatile memory (18) having a segmented programmable memory space for receiving data relating to a plurality of distinct applications, this memory space including (i) a first memory zone (A) segmented into several memory words each dedicated to storage of data relating to a determined application from among said plurality of distinct applications, (ii) a second memory zone (B), called a shared zone, segmented into several memory words each able to be allocated to storage of data relating to any application from among said plurality of distinct applications, and (iii) a third memory zone (C) containing indications relating to the allocation of memory words of said second memory zone, at least, and for determining which memory word or words of said second memory zone are allocated to storage of data relating to a given application from among said plurality o

Abstract: There is described an integrating circuit (20) for use with a photodetector (10) and an optical sensor (1) including such an integrating circuit. The integrating circuit comprises an operational amplifier (30) having a non-inverting input (32) connected to a non-zero bias voltage (VPD-BIAS), an inverting input (31) coupled to the photodetector (10), and at least one output (33). This integrating circuit further includes an integrating voltage storage device (25) having a first terminal coupled to the operational amplifier output and a second terminal coupled to the operational amplifier inverting input, and switching circuitry for controlling timing of the integrating circuit and switching the integrating circuit between a reset phase and an integration phase.

Abstract: There are described a system and a method of detecting the passage of persons or objects through an entry-exit (4) of a delimited space (2). The direction of passage is detected on the basis of the reception, by a portable electronic unit (40) with which the person or the object is equipped, of first and second electromagnetic signals (a, b) respectively transmitted in respective spatially separate and partially overlapping first and second communication regions (A, B) each crossing an entry-exit zone (32) defined by the entry-exit. The first and second electromagnetic signals are transmitted substantially in phase at the same frequency and each comprises an identical message portion (100), one of said first and second electromagnetic signals further comprising an additional message portion (150) identifying the corresponding communication region (A, B), transmission of the other of said first and second electromagnetic signals being interrupted during the transmission of said additional message portion.

Abstract: There is described a method, a sensing device as well as an optical pointing device including a sensing device for comparing light intensity between pixels. Light intensity between pairs of pixels of a photodetector array is compared as follows. First and second output signals generated by the photosensitive elements of a first and a second pixel of each pair are integrated over time to respectively provide first and second integrated signals. Integration of the first output signal is interrupted at the end of a first time period and the resulting first integrated signal is stored. Integration of the second output signal is continued until the end of a second time period and the resulting second integrated signal is compared to the stored first integrated signal to provide an output signal representative of an edge condition between the first and second pixel.

Abstract: The present invention concerns a data updating method for a non-volatile memory broken down into a plurality of similar memory subdivisions that can be erased independently of each other and among which at least two memory subdivisions (SRA, SRB) are reserved for updating data contained in each of said subdivisions (SM). The method implemented enables the execution time of an update to be reduced by simultaneously erasing the non-reserved memory subdivision (SM) to be updated and an unused reserved memory subdivision (SRB).

Abstract: A voltage multiplier circuit in particular for programmable memories is supplied by a low voltage. This circuit includes an oscillator which generates a clock signal and a charge pump circuit controlled by the clock signal. The charge pump boosts a DC supply voltage to a high voltage which is looped back to a voltage feedback regulator. A multiplexer which is placed between the oscillator and the charge pump, receives a gating signal from the regulator which depends on the comparison of the high output voltage to a determined regulation voltage.

Abstract: Electronic device for monitoring the temperature of a medium ensures that the temperature has not reached pre-established index limit values. The device includes contacts for closing an electric charge flow circuit when the temperature reaches an index limit value, an electric charge storage component connected to the charge flow circuit when the contacts close, the charges remain stored as long as the temperature does not reach one of its index limit values, and is able to flow through the charge flow circuit when the circuit is closed by the contacts, the charge storage not returning to the charge state which they had before the charge flow circuit closed if the latter opens again, and a provision for reading enabling the charge state to be determined.

Abstract: There is described a sensing device for an optical pointing device comprising a plurality of pixels, each one of the pixels comprising a photosensitive element for generating a pixel output signal in response to radiation reflected from an illuminated portion of a surface, the sensing device further comprising processing means for determining, based on said pixel output signals, a measurement of relative motion between the sensing device and the illuminated surface and for generating cursor control signals based on this measurement. The sensing device further comprises circuit means for summing the pixel output signals of subsets of pixels including at least two pixels and for generating, for each of the subsets of pixels, a summed output signal, the processing means determining the measurement of relative motion based on the summed output signals.

Abstract: A high-voltage regulator circuit (1) delivering at least a first regulated output voltage (VREG1, VREG2) from a high input voltage (VHV), this regulator circuit including an external regulation device (2) including an input terminal (21) to which said high input voltage is applied, an output terminal (22) at which said first regulated output voltage is delivered, and a control terminal (23) connected to a control circuit (10) of the external regulation device. The external regulation device (2) is controlled by a differential amplifier (4) to the inputs of which are respectively applied a divided voltage proportional to the first regulated output voltage and a determined reference voltage (VREF), the output of this differential amplifier controlling the conduction state of the external regulation device (2) through a high-voltage MOSFET transistor (3) connected via its drain to the control terminal (23) of the external regulation device (2).

Abstract: The integrated circuit is provided with integrated calibrating circuit in order to calibrate at least one electronic module supplying at its output a reference voltage or a time base signal or a reference frequency signal. Said calibrating means are defined by a microcontroller which receives via an input pad of the integrated circuit an external reference signal which is compared to an internal reference signal of the reference module in order to be able to calibrate in an autonomous manner the integrated reference electronic module as a function of the external reference signal. The final calibrating parameters are permanently stored with an associated signature in a memory so that each time that voltage is subsequently applied to the circuit the final calibrating parameters are automatically applied to the corresponding reference module.

Abstract: Transponder (2) associated with a communication system for various different applications having different security levels. This transponder includes means (18, 26, 40, R) allowing the maximum communication distance between the transponder and a reader (4) to be varied as a function of the application selected or activated. A code, which determines the opening or closing of the switch (40) is associated with each application. In a first group of embodiments, the equivalent impedance of the electronic unit associated with the antenna (6) is varied, whereas in another embodiment, the electric characteristics of the antenna itself are varied.

Abstract: System for communication between a plurality of transceivers, transmitting in particular at a high frequency and arranged respectively in a plurality of delimited spaces each having at least one entrance, and portable electronic units fitted with means for radio-communication with the plurality of transceivers, in particular with a view to detecting each of them penetrating one of the delimited spaces. The communication between the transceivers and the portable electronic units for neighboring delimited spaces is effected at different exclusive frequencies or frequencies of sub-sets of frequencies associated with the exclusive frequencies.

Abstract: The present invention concerns a low frequency oscillator device including a quartz resonator (1) and an electronic maintenance circuit for maintaining the vibrations of said quartz resonator. According to the present invention, the quartz resonator is arranged to vibrate according to a torsional mode and therefore has a single cutting angle defined by a rotation at a determined angle (&thgr;) about the crystallographic axis X of the quartz crystal. This resonator includes in particular at least one undesired fundamental flexural vibrating mode at a first frequency and a desired fundamental torsional vibrating mode at a second frequency higher than said first frequency. Moreover, the electronic maintenance circuit is an inverter circuit (2) whose transconductance value (gm) is determined such that said device cannot oscillate according to the undesired fundamental flexural vibrating mode but according to the desired fundamental torsional vibrating mode of said resonator.