Abstract: An incandescent lamp has an attachment for connection to a two-wire electrical power line and a bulb containing a radiating element. At least two filaments are housed in the bulb and constitute the radiating element, and circuitry has an input connected to the electrical power line and an output connected to filaments. When a selection signal indicating the desired brightness is passed to circuitry, preferably along the electrical power line, and acts in such a way that circuitry selectively provides a feed to filaments on the basis of the selection signal, a change in brightness is obtained without deterioration of the color characteristics because the filaments operate under their rated operating conditions. The change in brightness will not be continuous, but discrete, but is more than acceptable for domestic requirements even with a small number of filaments.
Abstract: The invention relates to a method for detecting a threshold-crossing of a back electromotive force (bemf) measured in one phase of a multiple-phase motor, the one phase being set at a high impedance while at least one other phase is supplied by pulse-width modulation signal. The method includes the step of comparing the bemf with a threshold. The method includes, prior to the step of comparing, the steps of sampling the bemf during on-periods of the pulse-width modulation signal, and holding the bemf during off-periods of the pulse-width modulation signal.
Abstract: A programmable reference voltage source includes a nonvolatile memory cell, the floating-gate region of which stores electric charges determining a memorized threshold value. The drain terminal of the cell is biased at a constant voltage, and the source terminal is coupled to a constant-current source and to the inverting input of an operational amplifier having the noninverting input coupled to a reference voltage and the output coupled to the gate terminal of the cell. By defining the threshold of the cell as the gate voltage (measured with respect to ground) capable of causing the cell to be flown by the current set by the current source, the output voltage of the operational amplifier equals the threshold and may be used as a programmable reference in analog memories.
Type:
Grant
Filed:
September 30, 1997
Date of Patent:
May 4, 1999
Assignee:
STMicroelectronics, S.r.l.
Inventors:
Alan Kramer, Roberto Canegallo, Mauro Chinosi, Giovanni Gozzini, Pier Luigi Rolandi, Marco Sabatini
Abstract: A microphone device having input terminals for receiving an input analog signal and output terminals to produce an output digital signal. The microphone device includes a converter circuit having input terminals coupled to the input terminals of the microphone device and an output terminal coupled to the output terminals of the microphone and an output terminal coupled to the output terminals of the microphone device.
Type:
Grant
Filed:
May 24, 1996
Date of Patent:
March 23, 1999
Assignee:
SGS-Thomson Microelectronics, S.r.l.
Inventors:
Sandro Dalle Feste, Marco Bianchessi, Nadia Serina
Abstract: To check the programming of a nonvolatile memory cell storing an actual threshold value, the drain terminal of the cell is biased at a constant voltage; the gate terminal is biased at a check voltage; the cell is supplied with a predetermined current to determine a gate-source voltage drop related to the actual threshold value; and the voltage at the source terminal is supplied to an input of an operational amplifier. In an open-loop configuration, the desired threshold value of the set predetermined current is supplied as the check voltage; the amplifier compares the source voltage with the ground; and switching of the amplifier indicates the desired threshold value has been reached. In a closed-loop configuration, the output of the operational amplifier is connected directly to the gate terminal of the cell, and supplies the desired threshold value directly.
Type:
Grant
Filed:
September 30, 1997
Date of Patent:
March 9, 1999
Assignee:
SGS-Thomson Microelectronics, S.r.l.
Inventors:
Alan Kramer, Roberto Canegallo, Mauro Chinosi, Giovanni Gozzini, Pier Luigi Rolandi, Marco Sabatini
Abstract: The present invention concerns an auto-saving circuit for programming configuration elements of non-volatile memory cells organized in a cells matrix in a memory device integrated on a semiconductor. The auto-saving circuit is inserted between a first and a second power supply reference voltage and is powered also by programming voltages generated inside the memory device to produce at an output programming signals of the configuration elements. The auto-saving circuit includes a first and a second circuit portion, one for each signal output and each powered by a respective programming voltage and each including a switching network with at least one high threshold transistor and decoupling elements to give inertia to the circuit against electrostatic discharges or accidental power supply variations.