Em Microelectronic-marin Sa

Arthur Descombes

Zoran Randjelovic

Marc Degrauwe

Tindaro Pittorino

Marcel Bruelhart

The invention concerns a test method for a transmitter-receiver circuit. This transmitter-receiver circuit includes an antenna, connected to a processing unit, arranged for receiving signals and converting their frequency. The transmitter-receiver circuit also includes a power amplifier connected to said antenna and arranged for sending transmission signals. The transmitter-receiver circuit also includes a test module, characterized in that it includes the steps consisting in:

Operation test method for a circuit for transmitting and receiving signals

The DC-DC converter () is for integration in a low power transceiver (). The converter is able to supply an output voltage that is higher than the input voltage. The converter includes two distinct variable voltage regulator circuits (and). The first variable voltage regulator circuit () is arranged to operate at a first frequency and a second variable voltage regulator circuit () is arranged to operate at a second frequency, which is lower than the first frequency. The converter further includes switching means connected to each variable voltage regulator circuit for selecting one of the two regulator circuits to switch on.

DC-DC converter for a low power electronic circuit

The invention concerns a method of verifying the proper working of a transponder mounted on a rotating mobile element of a vehicle, characterized in that it includes the steps of: a) measuring a temperature value by means of a temperature sensor connected to the transponder; b) detecting breach of a overheat threshold; c) a monitoring operation carried out by a reader arranged in the vehicle and provided for communicating with the transponder, consisting in executing a command on one of the temperature sensitive elements of the transponder; d) the reader determining the state of the transponder as a function of the response or absence of any response to the command to be executed: (i) if the response is correct, the transponder is operational; (ii) if the response is incorrect, or in the absence of any response, the transponder is not operational.

Method of verifying the proper working of a transponder mounted on a vehicle wheel

A high-voltage regulator circuit ( ) delivering at least a first regulated output voltage (V , V ) from a high input voltage (V ), this regulator circuit including an external regulation device ( ) including an input terminal ( ) to which said high input voltage is applied, an output terminal ( ) at which said first regulated output voltage is delivered, and a control terminal ( ) connected to a control circuit ( ) of the external regulation device. The external regulation device ( ) is controlled by a differential amplifier ( ) to the inputs of which are respectively applied a divided voltage proportional to the first regulated output voltage and a determined reference voltage (V ), the output of this differential amplifier controlling the conduction state of the external regulation device ( ) through a high-voltage MOSFET transistor ( ) connected via its drain to the control terminal ( ) of the external regulation device ( ).

High-voltage regulator including an external regulating device

A method and a device for generating a substantially temperature independent current (I ) are described. To generate this current (I ), a conventional current generator circuit including an operational amplifier ( ) controlling a transistor ( ) having one ( ) of its current electrodes ( ) connected to a resistor ( ) and to an input terminal ( ) of the operational amplifier ( ), is used. According to the invention, a temperature stable input voltage (Vin) is applied at the other input terminal ( ) of the operational amplifier ( ), and the latter is arranged so that it has an offset voltage (Vos(T)) between its input terminals ( ) 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 ( ) such that the current generated (I ) is substantially temperature independent. According to the invention, the geometry of the differential pair of the operational amplifier ( ) is acted upon to generate the offset voltage (Vos(T)).

Method for generating a substantially temperature independent current and device allowing implementation of the same

The invention concerns a protective circuit ( ) for protecting a rechargeable battery ( ) against currents of too high intensity. The protective circuit ( ) includes detection and comparison means ( ) for generating a control signal (OVRC) in response to the comparison of a reference voltage (V ) and a measuring voltage (V ) representative of the charge or discharge current (I , I ) passing through the battery ( ). According to the invention, the detection and comparison means ( ) include adjustment means ( ) for compensating a temperature dependence of the measuring voltage (V ) and/or the reference voltage (V ), these adjustment means ( ) including means for generating diode voltages (V to V ).

Protective circuit for battery

The invention concerns a temperature level detection circuit including means (B,, B,, B,) for generating diode voltages (V,to V,) and calculating means including capacitive elements (,) and switching means (SW,to SW,) arranged to connect selectively and sequentially, during first and second phases, the capacitive elements (,) to the means generating said diode voltages (V,to V,). 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 (T,) defined as the temperature value for which the equation &agr;,(V,&minus;V,)&plus;&agr;,(V,&plus;&agr;,(V,&minus;V,)) becomes zero, where &agr;,, &agr;,, and &agr;,are first, second and third proportionality coefficients determined by the values of the capacitive elements.

Temperature level detection circuit

An apparatus equipped with a battery, such as an electrical toothbrush, receives from a charging device a charging voltage which adapts to the charged condition of the battery and on whose over-discharging is correspondingly small. On the one hand the apparatus comprises a series circuit between a capacitor and a diode which is connected to the charging device parallel to the battery, wherein the diode is arranged in the forward direction. On the other hand in series to the battery there is arranged an electronic switch which periodically for a short time interrupts the charging procedure of the battery. In each case during such an interruption the charging apparatus is unloaded and its voltage increases jump-like by which means the capacitor can be charged via the diode. In each case with a closed switch, i.e. on loading the charging apparatus by the battery, the capacitor supplies a further relatively high impedance load so that this independently of the value of the charging voltage may be supplied with a sufficiently high and constant voltage.

Battery operated apparatus

This programming arrangement for a non-volatile memory incorporated in the inner circuit of a timepiece for adjusting the frequency of the time base thereof includes a support provided with a connector to be plugged in in place of the energy cell. The rate of division of the frequency divider is adjusted by the introduction into the memory of a number k representative of the frequency difference between the time base frequency and a standard frequency. To effect this the arrangement comprises an electronic circuit external to the timepiece and which is coupled thereto by the connector. The electronic circuit introduces the number k into certain predetermined stages of the divider. When such number k is thus introduced the state of such stages is blocked by the inner circuit of the timepiece such state then being transferred into the non-volatile memory.

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Kerzers, Switzerland

Arthur Descombes