Abstract:
A self-aligned double-polysilicon type bi-polar transistor with a heterojunction base comprises a semiconducting heterojunction region lying over an active region of a semiconductor substrate and over an isolating region delimiting the active region, and incorporating the intrinsic base region of the transistor. An emitter region situated above the active region and coming into contact with the upper surface of the semiconducting heterojunction region. A polysilicon layer forming the extrinsic base region of the transistor, situated on each side of the emitter region and separated from the semiconducting heterojunction region by a separation layer comprising an electrically conducting connection part situated just outside the emitter region. This connection part ensures an electrical contact between the extrinsic base and the intrinsic base.
Abstract:
A voltage regulator includes a regulation MOS transistor with low serial resistance having a first terminal connected to a voltage source and a second terminal connected to the output of the voltage regulator and an amplifier having an output driving a gate of the transistor. The gate is driven based upon a difference between a reference voltage and a feedback voltage. The regulator may also include an anti-overshoot switch with a first terminal connected to the gate of the regulation MOS transistor and a second terminal is taken to a potential for turning the regulation MOS transistor off. A switch controller closes the switch when the output voltage of the regulator is higher than a first threshold. The first threshold may be higher than the nominal value of the output voltage.
Abstract:
A method for the correction of an erroneous bit in a string of bits includes providing, in the string of bits, for a first parity bit computed from the other bits of the string of bits at a point in time when the erroneous bit was valid. The correct value of the erroneous bit is computed by using the other bits of the string of bits comprising the parity bit. The erroneous bit is then replaced by its correct value. The method is applicable to error correction circuits in EEPROM memories.
Abstract:
A pseudo-random number generator includes a first generator for producing a sawtooth waveform signal having a first frequency, and a second generator for producing a pulse signal having a second frequency. A sampling circuit samples the sawtooth waveform signal and the pulse signal for generating a sample signal of the sawtooth waveform signal at the second frequency. A coding circuit codes the amplitude of the sample signal to supply binary values. The pseudo-random number generator has applications in integrated circuits which are used in contact type or contactless IC cards.
Abstract:
A serial input/output memory is able to read data in the memory upon reception of a partial read address in which there are N least significant bits lacking to form a complete address. The read-ahead step includes: simultaneously reading the P first bits of M words of the memory having the same partial address; when the received address is complete, selecting the P first bits of the word designated by the complete address and delivering these bits at the serial output of the memory; reading P following bits of the word designated by the complete address during the delivery of P previous bits and delivering these bits at the serial output of the memory when the P previous bits are delivered.
Abstract:
A device for detecting the application of a high voltage signal to an internal node of an integrated circuit includes a high-voltage divider circuit and a threshold detection circuit. The threshold detection circuit receives a signal given by the output of the divider circuit, and provides a threshold crossing detection signal at an output thereof based upon the signal crossing a threshold. The detection circuit is connected between the logic supply voltage and ground, and further includes a negative feedback loop. The negative feedback loop is connected to the output of the divider circuit to limit the voltage build-up of the high voltage signal at the output thereof after the crossing of the detection threshold by the signal.
Abstract:
In an electronic component including a two-way bus through which data elements travel between peripherals and a central processing unit at the rate of a clock signal, the central processing unit and at least one of the peripherals each includes a data encryption/decryption cell. Each data encryption/decryption cell uses the same secret key. The secret key is produced locally at each clock cycle in each cell from a random signal synchronous with the clock signal, and is applied to each of the cells by a one-way transmission line.
Abstract:
A variable gain amplifier includes a pair of amplification and recentering branches. Each branch includes: a resistive element of variable resistance configured to be driven by a variable gain controller; a digitally-driven variable current source configured to be driven by a compensation current driver unit; a first transistor comprising a gate terminal coupled to an input terminal of the variable gain amplifier, and a source terminal coupled to a first terminal of the resistive element; and a second transistor comprising a gate terminal coupled to a drain terminal of the first transistor, and a source terminal coupled to an output terminal of the variable gain amplifier.
Abstract:
A transformer of the balanced-unbalanced type includes a primary inductive circuit and a secondary inductive circuit housed inside an additional inductive winding connected in parallel to the terminals of the secondary circuit and inductively coupled with the primary circuit and the secondary circuit.
Abstract:
A device can be used for compensating bandwith mismatches of time interleaved analog to digital converters. A processor of the device determines, for each original sample stream, an estimated difference between the time constant of a low pass filter representative of the corresponding converter and a reference time constant of a reference low pass filter, and uses this estimated difference and a filtered stream to correct the original stream and deliver a corrected stream of corrected samples.