Sgs-thomson Microelectronics S.r.l.

Sgs-thomson Microelectronics S.p.a.

Other

Stmicroelectronics S.r.l.

Magneti Marelli S.p.a.

Magneti Marelli

Thomson Microelectronics

Giampietro Maggioni

Marco Morelli

Massimiliano Brambilla

Michelangelo Mazzucco

Fabio Marchio

Maurizio Gallinari

Francesco Tricoli

Mirco Contucci

Bruno Murari

Paolo Menegoli

Valerio Giorgetta

Claudio Serratoni

Paolo Mastella

A method for generating a fault signal in a system voltage regulator by a phase signal includes detecting the system voltage and phase signal; comparing the system voltage and phase signal with respective fault levels; and generating a fault signal upon either the system voltage or the phase signal falling below the respective fault level of the fault levels. The fault signal generating method also inhibits generating a fault signal using a drive signal of the system voltage regulator. A diagnostic circuit for a system voltage regulator is also disclosed.

Method for generating a fault signal in a voltage regulator and corresponding control circuitry for a system voltage regulator

The short-circuit detecting device includes a current generator for generating a current (I ) of predetermined intensity, selectively into or out of the terminal (IN), and a first voltage comparator connected to the terminal (IN) and connected to the current generator in a manner such that the generator generates a current (I ) in the inward direction and in the outward direction relative to the terminal (IN), respectively, when the voltage between the terminal (IN) and the ground is greater than a first level and less than a second level, respectively. The first level is greater than or equal to the second. The device also includes a second voltage comparator for supplying a first and a second signal, respectively, when the voltage between the terminal (IN) and the ground is close to the supply voltage (Vcc) and close to the ground potential (gnd), respectively, and a processing circuit connected to the second comparator for detecting whether the first or the second signal, respectively, persists for a predetermined period of time. In this case, an output signal (F_Vcc; F_gnd) is supplied which is indicative of a short-circuit of the terminal (IN) to the supply (Vcc) or to ground, respectively.

Device for detecting short-circuits

A circuit comprises a measurement resistor in series with a heater, a detector circuit for providing a signal indicative of the current flowing in the resistor, switching devices for controlling the connection of the heater to a voltage source and the connection of the measurement resistor in the supply circuit comprising the source and the heater, and a control unit arranged to drive the switching devices in a manner such that each time the heater is activated, the measurement resistor is kept disconnected from the supply circuit of the heater for a predetermined period of time and the measurement resistor is then connected in the supply circuit of the heater.

Heater control circuit

A double half-wave rectifier circuit with earth shift using an input differential amplifier and two current mirrors in cascode configuration in such a way that the input current is transferred to the output via one or the other of the current mirrors depending on whether the input signal voltage is greater than or less than an input reference voltage and therefore the current is positive or negative.

Double half-wave rectifier circuit having a wide input dynamic range

An injector control circuit for a motor vehicle electronic injection system utilizing current recirculation to control an injector actuation winding provided with a circuit configuration containing a constant current generator operable to eliminate the problems of instability and sensitivity to supply line interruptions to which prior art control circuits are subject.

Driver circuit for an injector

A circuit for regulating the charging voltage to a battery and connected to the field inductor (IND) of an alternator (ALT) which supplies that voltage. It is connected by a control cable to the battery and comprises an electric path, extending between a terminal for connection to the alternator and ground, which is only activated when the battery voltage drops below a predetermined threshold value. This electric path comprises a switch (TSW) driven from a control circuit (COMP1,T4) which sense the battery voltage, and when activated, the voltage drop across the path is substantially equal to that of the regulated voltage. The control circuit also senses breakage in the battery sensing cable, and ceases driving the alternator when this occurs.

Automotive voltage regulator and charging system

A drive circuit fault detection device comprising a discriminating circuit generating a digital signal, the level of which indicates a fault; and an identifying circuit generating a binary-coded signal indicating the type of fault, i.e. ground shorting of the drive circuit or an open load. The discriminating circuit comprises a resistive network connected to the output of the drive circuit, for generating a voltage indicating correct connection of the load or a fault on the drive circuit and a comparator for comparing the generated voltage with a reference voltage and supplying the digital signal at its output. The identifying circuit comprises a current mirror circuit generating an output voltage having two different logic levels in the event of short circuiting or an open load, respectively, and a combination circuit for generating the binary-coded output signal.

Drive circuit fault detection drive

The contrasting requirements of low power consumption during operation and ability to function under drastic drops of the supply voltage at start-up of output power stages of an electric system of self-generation and recharge of a storage battery, are satisfied by an output power driving stage composed of a bipolar transistor and a field effect transistor, functionally connected in parallel to each other and having independent control terminals. A control signal is selectably switched either to the base of the bipolar output transistor or to the gate of the field effect output transistor, depending on the level of the supply voltage. A comparator comparing the voltage present on the supply node with a reference voltage controls a selection switch. The low threshold of the bipolar transistor ensures functioning at start-up, while the field effect transistor provides a low power consumption during normal running conditions.

Output stage, and automotive regulator, with supply-dependent selection

An inductive load drive device which has a switch defining an output terminal connectable to an inductive load between the output terminal and a reference potential line is provided. A first current recirculating branch is connectable parallel to the load and a control opens and closes the switch so that the load is supplied with current rising to a first predetermined value in a first increasing phase and falling to a second predetermined value in a first recirculating phase. The device detects a short-circuit between the output terminal of the control device and the reference potential line with a first current sensor for detecting current flow in the first recirculating branch during the first recirculating phase. A fault signaling circuit connected to the first current sensor produces a short-circuit signal in the absence of current in the first recirculating branch during the first recirculating phase.

Circuit for detecting short-circuiting of inductive load drive devices

A circuit comprising a switch series connected to a load; a first and second current recirculating branch alternately connectable parallel to the load, for reducing the current in the same; and a logic control unit for opening and closing the switch and recirculating branches, so that the load is supplied with a current rising to a peak value and then falling rapidly to and oscillating about a lower hold value; a transistor being provided for reducing the voltage supplied to the load by the first recirculating branch at the end of the fast fall phase, so as to eliminate uncontrollable operating zones and prevent the load current from falling below the hold value.

Inductive load drive circuit, particularly for fuel injections

A voltage stabilizer with a very low voltage drop includes a series voltage regulator circuit having a first PNP transistor connected to an input terminal of the stabilizer via a second PNP transistor and being connected to ground via a capacitor. The stabilizer has biasing and switching circuits disposed between the input terminal thereof, a base terminal of the second transistor and ground.

Voltage stabilizer with a very low voltage drop designed to withstand

This voltage reference circuit has high thermal stability and minimal bulk and comprises a transistor defining a base-emitter junction having a voltage drop which varies in a non-linear manner as a function of temperature and resistors connected in series to the junction, the junction and the resistors being interposed between a ground line and the output terminal. A compensation transistor generates a compensation current which varies as a function of temperature so as to produce a voltage drop with a behavior substantially opposite to the previous voltage drop upon reaching the switching on temperature of the transistor.

Voltage reference circuit with linearized temperature behavior

A circuit for recirculating an inductive load's (L) discharge current through the driving power switching transistor (Tpw) utilizes a control transistor (Tc) of opposite polarity to that of the power transistor and capable of withstanding a minimum fraction (1/.beta.) of the discharge current. The circuit has the advantage of allowing recirculation of current with a fixed overvoltage independent of the value of the supply voltage, without requiring additional power devices. The circuit may also be provided with means (D1, D2 and DZ1) to turn-on the control transistor in the presence of concomitant supply overvoltages to protect the power device from dumping effects.

Transitory current recirculation through a power switching transistor

An integrated circuit for driving inductive loads comprises at least one substrate and a plurality of separate epitaxial wells, and has at least one output terminal for connection to an inductive load and a reference terminal for connection to a reference voltage. To reliably isolate the different epitaxial wells in each operating state, the circuit comprises diodes interposed between the substrate on one side and the output and reference terminals on the other to set the substrate to the reference potential when the potential on the output terminal is greater than the reference potential and to set the substrate to the output potential when the latter becomes smaller than the reference potential.

Growing community of inventors

Cornaredo, Italy

Giampietro Maggioni