Abstract: The present invention concerns the field of microstructures and in particular microstructures made via CMOS technology on semiconductor substrates intended to undergo micro-machining by wet chemical etching, in particular by a KOH etchant.

Abstract: A method and a device for generating a substantially temperature independent current (I1) are described. To generate this current (I1), a conventional current generator circuit including an operational amplifier (11) controlling a transistor (12) having one (12a) of its current electrodes (12a, 12b) connected to a resistor (13) and to an input terminal (11b) of the operational amplifier (11), is used. According to the invention, a temperature stable input voltage (Vin) is applied at the other input terminal (11a) of the operational amplifier (11), and the latter is arranged so that it has an offset voltage (Vos(T)) between its input terminals (11a, 11b) having a temperature dependence, this offset voltage (Vos(T)) and the input voltage (Vin) being adjusted to compensate for the temperature dependence of the resistor (13) such that the current generated (I1) is substantially temperature independent.

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 said plurality of transceivers, in particular with a view to detecting each of them penetrating one of said delimited spaces. The communication between the transceivers and the portable electronic units for neighbouring delimited spaces is effected at different exclusive frequencies or frequencies of sub-sets of frequencies associated with said exclusive frequencies.

Abstract: Method for welding two end portions (6, 8) of a coil (not shown) onto two electric contact pads or bumps (24, 26) of an integrated circuit (2) or an electronic unit of small dimensions. This welding method is characterised in that, prior to the actual welding step, a preliminary step is provided consisting in removing at least partially the insulating sheath from the electric wire (10) at least at the locations of the two end portions (6, 8) provided for the welding onto said electric contact pads or bumps (24, 26). The insulating sheath is removed locally by means of heat application, in particular using a heating press (58) working at a sufficiently high temperature to melt or sublimate the insulating sheath. The welding step is achieved at a much lower temperature than the temperature of the preliminary step, which allows the heat and mechanical stress to be reduced for the integrated circuit (2) and the bumps (24, 26) during welding of the ends (6, 8) onto said bumps.

Abstract: The invention concerns a protective circuit (10) for protecting a rechargeable battery (1) against currents of too high intensity. The protective circuit (10) includes detection and comparison means (30, 31, 32) for generating a control signal (OVRC) in response to the comparison of a reference voltage (VREF) and a measuring voltage (VM) representative of the charge or discharge current (ICH, IDCH) passing through the battery (1). According to the invention, the detection and comparison means (30, 31, 32) include adjustment means (32) for compensating a temperature dependence of the measuring voltage (VM) and/or the reference voltage (VREF), these adjustment means (32) including means for generating diode voltages (VBE1 to VBE5).

Abstract: The present invention concerns a control device (21) for a liquid crystal display cell (1) including electrodes (1.1a; 1.1b; 1.1c) forming segments and/or symbols. This device includes control means (33a; 33b; 33c) for providing control signals to said electrodes; and a matrix network of connection paths (45; 47; 49; 50) whose columns (49; 50) are connected to said control means, and whose lines (45; 47) are connected to receive address signals and data signals representative of said control signals. This device further includes switching means (52) arranged at each of the intersections of said network, each of said switching means being arranged so as to be able to be switched permanently into the conducting state or the non conducting state, in accordance with a circuit layout predetermined as a function of said cell.

Abstract: The present invention concerns an oscillator (20) intended to supply a periodic electric voltage (Vo) at a predetermined frequency (f). This oscillator includes: a reference source (23) able to provide a reference voltage (Vref), this reference source including a resistor (R) linked to said voltage; and supply means (24) able to receive the reference voltage and to supply said periodic voltage at said predetermined frequency, the supply means having a first temperature coefficient (&agr;24) so this frequency can vary under the influence of the temperature. This oscillator is characterised in that the resistor is formed to give the reference source a second temperature coefficient (&agr;23) equal to the first temperature coefficient, so that the temperature has the same influence on the reference voltage and on the supply means, which allows the periodic voltage to be supplied independently of the temperature.

Abstract: The present invention concerns a method for measuring a chip integrated structure (1) including at least one coil (5) having a plurality of turns (6). The present invention is characterized on the following steps: measuring the resistance across the terminals of first and second portions of said coil (5), corresponding to two different numbers of turns of the coil; computing the ratio of the measured resistances across the terminals of first and second portions of the coil (5); comparing the ratio to a constant measured from a sample of resistance measurements made on coils of identical geometry; and determining the presence or the absence of a short circuit between at least two turns of one of said portions of said coil (5), when the ratio is different from or equal to said constant respectively. The present invention further concerns an integrated circuit which is able to allow implementation of the above mentioned measuring method.

Abstract: The object of the procedure according to the present invention is to characterise a voltage or current converter (20) intended to be connected to a capacitive circuit (32) arranged so as to provide a capacitance difference (C1−C2) to the converter. Said converter is arranged so as to be able to receive the capacitance difference provided by the circuit, and to provide an output voltage (Vo) which is a function of the capacitance difference and a bias signal. This procedure is characterised in that it includes a sequence of steps which consist in varying the bias signal, while keeping the capacitance difference constant and measuring in response the output voltage. One advantage of such a procedure lies in the fact that it allows the electric performance of the converter to be determined independently of the error link to the capacitance measuring.

Abstract: The electronic memory (2) includes blocks (M1 to MN) associated respectively with protective sequences (P1 to PN) and decision units (D1 to DN) which control access to the memory blocks. The protective sequences include at least two bits. In order to protect the memory blocks against physical actions which could vary the inscribed code, access to a block is closed when the corresponding protective sequence has identical logical states.

Abstract: A base station (13) for a contactless interrogation system includes an oscillating device (23) supplying a control signal having a frequency which is adjustable via adjusting circuits (21, 22), a circuits (24) for controlling an antenna connected to the base station (13) for transmitting information, decoding circuits (25, 26, 27) for decoding the information picked up by the antenna. The oscillating device (23) is a voltage controlled oscillator which is phase locked by the adjusting circuits (21, 22), so that the control signal frequency is determined by the base station (13) and is adapted to the antenna. The sensitivity of a contactless interrogation system comprising the base station (13) of the present invention is improved, its structure is simpler and its different components can be integrated in a same chip.

Abstract: A control system for a bidirectional switch (20) is described, formed of a pair of MOFSET power transistors (210, 220) connected in anti-series, i.e. source to source or drain to drain. This control system includes means (50) allowing the state of conduction of the power transistors to be controlled, one or the other of these transistors being able to be set to the “OFF” state in order to assure the interruption of a current through the bidirectional switch (20). This control system includes coupling means (SWCPL, 510) enabling the gate of the power transistor at the “ON” state to be coupled at least temporarily with the gate of the power transistor at the “OFF” state when the bidirectional switch is switched on. This has the advantage of allowing, on the one hand, the use of high control voltages assuring a reduction in the series resistance of the power transistors, and, on the other hand, the bidirectional switch to be quickly switched on.

Abstract: The present invention concerns a method for optimising the etching rate of a polycrystalline layer having a predetermined composition comprising at least two chemical species arranged in the form of grains and grain boundaries, this layer having to be formed on a semiconductor substrate by a deposition process whose parameters have to be determined, and by a etching process with a reactive agent capable of reacting with the preponderant species in the layer. This method defines a structure parameter representing the grain boundary density of the layer, and comprises a step consisting in determining the smallest structure parameter value from among different samples having the predetermined composition, this value being considered as that which optimises the etching rate.

Abstract: The electronic assembly (20) includes an electronic unit (24), formed of an electronic module (26) and two conductive tongues (28, 30) defining two electric contact pads of said electronic unit, and a coil (22). The body (40) of the coil (22) is partially superposed onto the two tongues and fixed to the latter in a durable manner by means of a solidified binder material. The two ends of the coil are bonded respectively onto the two tongues (28, 30).

Abstract: The invention concerns a temperature level detection circuit including means (B1, B2, B3, 11, 12, 21, 31, 32) for generating diode voltages (VBE1 to VBE5) and calculating means including capacitive elements (51, 52, 53) and switching means (SW1 to SW4) arranged to connect selectively and sequentially, during first and second phases, the capacitive elements (51, 52, 53) to the means generating said diode voltages (VBE1 to VBE5). During the second phase, the calculating means generating a temperature signal representative of the temperature level being greater than or less than a determined temperature threshold (Tlimit) defined as the temperature value for which the equation &agr;1(VBE2−VBE1)+&agr;2(VBE3+&agr;3 (VBE5−VBE4)) becomes zero, where &agr;1, &agr;2, and &agr;3 are first, second and third proportionality coefficients determined by the values of the capacitive elements.

Abstract: The invention concerns a manufacturing method for electro-optical or electrochemical photovoltaic cells (10), each cell (10) including front (1) and back (2) substrates bonded to each other by a sealing frame in which an active medium is confined, each frame (12) having, for this purpose, a filling aperture (14), the cell (10) further including contact pads (8) for establishing the electric connection between the electrodes (4, 6) of said cell (10) and an electric supply or control circuit, a method wherein the cells (10) are separated individually by means of a water jet and the rectilinear edges (24) scribed on one of the substrates (1, 2) in order to allow the contact pads (8) of the cells (10) to appear are situated in a location not opposite the filling aperture (14) thereof.

Abstract: A voltage regulator circuit (1) able to detect a latch-up phenomenon disturbing the voltage to be regulated, to suppress such phenomenon and re-establish the voltage at a predetermined level. The circuit a bipolar transistor (2), a resistor (5) and substantially constant voltage supply means (6). The circuit (1) also includes voltage detection means (11) arranged to receive the regulated voltage (Vreg), and to supply a control voltage to said transistor (2) which can control the switching thereof between a conducting state and a blocked state, so that the transistor (2) is in the blocked state when latch-up causes the regulated voltage to drop below a first voltage level, and so that the transistor (2) is in the conducting state when the regulated voltage is lower than a second voltage level, the latch-up being suppressed below such level.

Abstract: A communication system comprising a base station (20) and a plurality of transponders (TR; 21 to 26), the base station (20) emitting an electromagnetic field (1) defining a communication volume (2) in which several transponders (21, 22, 23) are susceptible to be situated. The transponders are adapted to generate identification messages (30) in response to the electromagnetic field (1). The base station (20) is adapted to selectively communicate with each transponder by generating communication initiation signals (40) in response to the identification messages (30). Each transponder is adapted to open a communication window (60) in response to a communication initiation signal (40) during which information may be exchanged and/or commands may be sent.

Abstract: A manufacturing method for electronic components (1) including a coil (10), in which a distributing device (34), carrying a pay-out reel (24) on which is wound a winding wire (6), places the wire (6) in contiguous regular turns (8) onto a core (2), this method being characterised in that a flux of ionised air is forced to flow onto the coil (10) during manufacturing to remove electrostatic charges produced during the winding of the coil.

Abstract: The present invention concerns a circuit (30; 50) for supplying a first current (I3) to an external element (3), this current having to be supplied with high precision at a desired nominal value. The current supply circuit includes a first transistor (T3) through which the first current flows, an operational amplifier (A2) to a first input of which a reference voltage (Vref) is supplied, and to an output of which a control signal from the first transistor is supplied, and an external resistor (Re1; Re2). These the circuit is characterized in that it further includes a second transistor (T4) through which a second current (I4; I4/m) flows, said second current also flowing through the external resistor. Such an arrangement of the circuit according to the present invention allow the value of the first current to be trimmed with great precision to its nominal value.