Abstract: An OLED (organic light-emitting diode) passive-matrix display includes a display portion and a driver portion. The display portion includes a matrix of OLEDs for displaying information. The driver portion includes a monitor circuit and a voltage adjusting circuit. The voltage adjusting circuit has a power-up portion that generates a supply voltage based on a reference voltage. In response to an indication to switch modes, the voltage adjusting circuit switches to an operational mode wherein the supply voltage is generated based on the maximum voltage drop read across the OLEDs.

Abstract: An OLED (organic light-emitting diode) passive-matrix display includes a display portion and a driver portion. The display portion includes a matrix of OLEDs for displaying information. The driver portion includes a monitor circuit and a voltage adjusting circuit. The voltage adjusting circuit has a power-up portion that generates a supply voltage based on a reference voltage. In response to an indication to switch modes, the voltage adjusting circuit switches to an operational mode wherein the supply voltage is generated based on the maximum voltage drop read across the OLEDs.

Abstract: A regulated voltage-boosting device provides a charge-pump circuit, which has an input terminal receiving a first voltage and an output terminal supplying a second voltage higher than the first voltage. The regulated voltage-boosting device provides a plurality of voltage-boosting stages that can be selectively activated and deactivated. The regulated voltage-boosting device provides an automatic-selection circuit for activating a number of voltage-boosting stages which is correlated to the first voltage and to the second voltage.

Abstract: A circuit for detecting signals present on a bifilar voltage-supply and signal-transmission line, in which the signals are constituted by positive and negative variations of the supply potential of at least one of the wires of the line, the circuit including a low-pass filter connected to the two wires of the line in order to supply, at an output terminal of the filter, a constant reference potential substantially equal to the supply potential of a preselected one of the two wires, a first threshold comparator having a reference input terminal and a threshold input terminal connected, respectively, to the output terminal of the filter and to the preselected wire of the two wires, and a second threshold comparator having a reference input terminal and a threshold input terminal connected, respectively, to the preselected wire of the two wires and to the output terminal of the filter.

Abstract: A regulated voltage-boosting device provides a charge-pump circuit, which has an input terminal receiving a first voltage and an output terminal supplying a second voltage higher than the first voltage. The regulated voltage-boosting device provides a plurality of voltage-boosting stages that can be selectively activated and deactivated. The regulated voltage-boosting device provides an automatic-selection circuit for activating a number of voltage-boosting stages which is correlated to the first voltage and to the second voltage.

Abstract: The power supply device includes a DC-DC converter circuit having a power switch and a driving stage. The driving stage has a compensation terminal on which a compensation voltage is present, and which receives a biasing current. The driving stage includes a control circuit having an output terminal connected to a control terminal of the power switch and disconnection-detecting circuitry connected to the compensation terminal and generating a signal for permanent turning-off of the power switch when the biasing current drops below a current-threshold value. The driving stage moreover includes over-voltage detecting circuitry connected to the compensation terminal and generating a signal for temporary turning-off of the power switch when the compensation voltage exceeds a voltage-threshold value.

Abstract: Static current consumption in a low-side output drive stage is eliminated by employing a switch in series with a current generator that is employed for controlling the discharge process of the driving node (gate) of the output power transistor and by controlling the switch with the voltage that is present on the driving node of the out put power transistor.

Abstract: The power supply device comprises a DC-DC converter circuit including a power switch and a driving stage. The driving stage has a compensation terminal on which a compensation voltage is present and which receives a biasing current, said driving stage comprising a control circuit having an output terminal connected to a control terminal of the power switch and disconnection-detecting means connected to said compensation terminal and generating a signal for permanent turning-off of said power switch when the biasing current drops below a current-threshold value. The driving stage moreover comprises over-voltage detecting means connected to the compensation terminal and generating a signal for temporary turning-off of said power switch when said compensation voltage exceeds a voltage-threshold value.

Abstract: A current pulse generator with process-independent and temperature-independent symmetric switching times, includes a differential stage which is adapted to generate a transmission current and a circuit for driving the differential stage which is adapted to generate a control voltage for the differential stage. The generator also includes a circuit for compensating the variations in the values of degeneration resistors of the differential stage, to generate, with the differential stage driving circuit, a current for controlling the differential stage, to keep the switching times of the current pulses of the generator substantially unchanged and symmetrical despite variations in the manufacturing process of the generator and the temperature.

Abstract: A voltage regulator providing smooth variation of an absorbed current having a first capacitor parallel-connected to a load, which is in turn connected to a supply voltage; a transconductor coupled between the supply voltage and the load and whose output voltage supplies the load; a differential amplifier coupled between the output of the transconductor and the supply voltage, and further coupled to the input of the transconductor, a second capacitor coupled between the supply voltage and the input of the transconductor; and a pair of diodes coupled between the output of the transconductor and the first capacitor and configured to introduce a zero in the transfer function of the voltage regulator that is suitable to compensate for a pole generated by the first capacitor.

Abstract: The present invention is aimed at providing a method and a circuit for protecting the output stage of a power actuator against voltage transients of the surge type. In particular, it provides protection against voltage surge transients of the kind described by International Standard IEC 801-5, for a power transistor contained in the output stage of the actuator.The method of this invention provides for:the utilization of the power transistor (PW) intrinsic diode (DP) for dumping the transient energy to one of the supply generator terminals during a positive transient; andthe utilization of the power transistor (PW) restoration feature to the on state for dumping the energy thereinto during a negative transient, while simultaneously inhibiting the current limiting function.

Abstract: A protection circuit for at least one power transistor which has at least one control terminal and two main conduction terminals defining a main conduction path includes a first detection means designed to generate a first electrical signal approximately proportional to current flowing in the main conduction path. Second detection means are designed to generate a second electrical signal approximately proportional to voltage across the main conduction path. Multiplying means receive at input the first and second signals and are designed to generate an electrical product signal substantially corresponding to the product of at least the latter. A generator generates an electrical reference signal, and operational amplifier means receive at input the product signal and the reference signal and are designed to generate an electrical difference signal substantially corresponding to their difference.

Abstract: The purpose of the present invention is to protect the final transistor of a power actuator from short circuits and overloads with a completely integrated circuitry solution which would not influence the output impedance of the actuator and would permit having a limitation current constant and independent of the value of the output terminal of the actuator.

Abstract: A non-dissipative device for protecting an integrated circuit having multiple independent channels against overloading. The non-dissipative device includes an input terminal and an output terminal having an integrated switch connected therebetween which consists of an input portion, a logic gate with two inputs a control portion, and an output portion, all connected in series with one another. The device further includes a generating circuit for generating the on-times and off-times of the integrated switch, the generating circuit is connected between an output of the output portion and an input of the logic gate.

Abstract: Power consumption by the driving circuitry of an output stage, employing a slew-rate controlling operational amplifier, is reduced by modulating the level of the current output by the operational amplifier in function of the working conditions of the output stage. Switching delay may also be effectively reduced. An auxiliary current generator forces an additional current through the conducting one of the pair of input transistors of the operational amplifier only during initial and final phases of a transition, essentially when the slew rate control loop ceases to be effective. The boosting of the bias current through the conducting input transistor is determined by the degree of unbalance of the differential input stage of the operational amplifier, without the use of dissipative sensing elements.

Abstract: The turn-off delay time of a low-side driver (output power transistor), may be independently reduced and eventually made identical to the turn-on delay time by employing an auxiliary current generator that may be controlled by the same switching signal that controls a current generator employed for discharging the control node of the low-side driver, in order to provide an augmented discharging current during a first phase (only) of a turn-off process. The contribution to the capacitance discharge current provided by said third current generator is automatically interrupted by means responsive to the voltage present on the driving node of the low-side driver, when it approaches saturation.