Abstract:
A chip includes CPU (12), memories (13,14) for programs and data, peripheral units (18,19) for interacting with the outside world, and an internal RC oscillator (17) for providing clock signals. One of the peripheral units (18) includes a timer counter incremented at a frequency derived from the RC oscillator. The method does not try to change the frequency of the RC oscillator. Instead, an external calibration source (21) is connected to a capture input of the timer unit to provide a signal having a reference frequency, e.g. the mains frequency. The counter is sampled on active edges of that signal, and the sampled values are processed to derive a calibration ratio. After these calibration steps, a software correction is applied to parameters handled by programs stored in memory based on the calibration ratio to compensate for frequency variations of the RC oscillator.
Abstract:
Process for fabricating a transistor comprises producing source and drain extension regions, consisting in forming a gate region on a semiconductor substrate and in implanting dopants into the semiconductor substrate on either side of and at a certain distance from the gate of the transistor. The producing of the source and drain extension regions consists in forming an intermediate layer (Cl) on the sidewalls of the gate (GR) and on the surface of the semiconductor substrate. This intermediate layer is formed from a material that is less dense than silicon dioxide. The implantation of dopants (IMP) is carried out through that part of the intermediate layer that is located on the semiconductor substrate.
Abstract:
A control device is provided for a switching power supply having an output that supplies an output voltage. The switching power supply includes an inductor and two changeover switches for controlling coupling of the inductor. The control device includes a first capacitor for charging with continuous current from a 0 V voltage level, a second capacitor for discharging of the continuous current from a predetermined voltage level that is greater than the voltage level of a DC power supply, and a comparison circuit. The comparison circuit compares the output voltage of the switching power supply with voltage levels of the first and second capacitors and generates control signals for controlling the two changeover switches of the switching power supply. Also provided are switching power supplies having such control devices and a method for controlling a switching power supply.
Abstract:
A semiconductor device is provided that includes a semiconductor channel region extending above a semiconductor substrate in a longitudinal direction between a semiconductor source region and a semiconductor drain region, and a gate region extending in the transverse direction, coating the channel region, and insulated from the channel region. The source, channel, and drain regions are formed in a continuous semiconductor layer that is approximately plane and parallel to the upper surface of the substrate. Additionally, the source, drain, and gate regions are coated in an insulating coating so as to provide electrical insulation between the gate region and the source and drain regions, and between the substrate and the source, drain, gate, and channel regions. Also provided is an integrated circuit that includes such a semiconductor device, and a method for manufacturing such a semiconductor device.
Abstract:
A calibration device for a video circuit input stage comprises an analog-to-digital converter and an input capacitor constantly discharged by a power source and recharged by a charging circuit by means of a first and a second charging current. The charging circuit is controlled by a central processing unit receiving an estimate of the variation between the converter's output code and a clamp value.
Abstract:
A demodulator for an amplitude modulated alternating signal includes a peak detection circuit for extracting the reference modulating signal from the amplitude modulated alternating signal, and a first translation circuit for offsetting the level of the reference modulating signal by a value equal to the DC component to obtain an offset reference modulated signal. A comparison threshold generator circuit generates a comparison threshold to locate the start and the end of the modulation, and a comparator circuit compares the offset reference modulating signal with the comparison threshold for providing signals that cross the comparison threshold. An unregulated supply circuit provides a supply voltage to the different circuits.
Abstract:
The fabrication of an integrated circuit includes a first phase of producing an electronic chip and a second phase of producing at least one auxiliary component placed above the chip and of producing a protective cover which covers the auxiliary component. The first phase of producing the chip is effected from a first semiconductor substrate and comprises the formation of a cavity lying in a chosen region of the chip and emerging at the upper surface of the chip. The second production phase includes the production of the auxiliary component from a second semiconductor substrate, separate from the first, and then the placement in the cavity of the auxiliary component supported by the second substrate and the mutual adhesion of the second substrate to the upper surface of the chip lying outside the cavity. The second substrate then also forms the protective cover.
Abstract:
A receiver of a frequency-modulated signal representing a digital signal includes a down conversion unit or frequency translation unit to lower the frequency of the frequency-modulated signal and a digital demodulator to regenerate the digital signal from the lowered-frequency signal. The receiver furthermore includes a counter circuit to determine the number of periods of a reference signal from the frequency translation unit during a period of the lowered-frequency signal. The digital demodulator includes a computer unit to compute the period of the lowered-frequency signal from the number of periods of the reference signal.
Abstract:
A method for defining, on the upper surface of a substrate, two self-aligned areas, including the steps of depositing a protective layer; depositing a covering layer; opening the protective and covering layers at a location substantially corresponding to the desired border of the two areas; forming a spacer along the side of the opening, this spacer having a rear portion against said border and an opposite front portion; opening the protective and covering layers behind the rear portion of the spacer; and removing the protection layer to reach the rear portion of the spacer; whereby two self-aligned areas are defined on either side of the spacer length.
Abstract:
The present invention relates to a read amplifier (SA2) comprising a read stage (RDST), a reference stage (RFST) and a differential output stage comprising PMOS and NMOS type transistors. According to the present invention, the transistors of the differential stage (DIFST2) comprise only one PMOS transistor (TP3) and one NMOS transistor (TN3) in series, the PMOS transistor (TP3) having its gate linked to one node of the read stage (RDST), the NMOS transistor (TN3) having its gate linked to one node of the reference stage (RFST), the mid-point of the PMOS and NMOS transistors of the differential stage forming a data output node (DATAOUT) of the read amplifier. The read amplifier according to the present invention has the combined advantages of a short read time and a low electrical consumption. Application to EPROM, EEPROM and FLASH type non-volatile memories.