Infineon Technologies Ag

Richtek Technology Corporation

Infineon Technologies Austria Ag

Giovanni Capodivacca

Maurizio Galvano

Andrea Scenini

Giuseppe Bernacchia

Adolfo De Cicco

Jian-Rong Huang

Fabrizio Cortigiani

Paolo Milanesi

Giorgio Chiozzi

Kuo-Lung Tseng

Nicola Florio

Andrea Logiudice

Roberto Penzo

Andreas Eder

Maurizio Cda Galvano

A device for driving several light sources is provided, wherein the several light sources are arranged in a matrix structure; wherein the several light sources of the matrix structure are connected to a semiconductor device; wherein a portion of the semiconductor device corresponds to a light source of the matrix structure, wherein the portion of the semiconductor device comprises a diagnosis function which when activated is arranged for supplying an output diagnosis signal.

Driving several light sources

A device may include a plurality of cells. Each cell may include a field-effect transistor and a switch configured to selectively connect a second contact of the respective field-effect transistor with a common test line of the device. A controller of the device is configured to control the switch to be in a closed position. At least one pin is provided which is configured to apply a stress voltage to a common power line connected to a first contact with the field-effect transistor and to the common test line.

Device testing

A device for driving several light sources is suggested comprising a shift register comprising at least two cells, wherein an output of each cell controls one of the several light sources; wherein the at least two cells are connected in series and are driven by a clock signal; wherein each cell of the shift register comprises a flip-flop and a register; wherein the output of the flip-flop is connected with the input of the register; wherein the register is arranged to store the output of the register based on an update signal and wherein the output of the register controls one of the light sources; wherein the flip-flops of the at least two cells are filled with a data signal based on the clock signal; and wherein after a predetermined number of cycles of the clock signal the update signal is conveyed to the registers driving the light sources according to the values stored in the flip-flops of the cells.

A control circuit can control the operation of a switching converter to provide a regulated load current to a load. The switching converter includes an inductor and a high-side and a low side-transistor for switching the load current provided via the inductor. A digital modulator is configured to provide a modulated signal having a duty cycle determined by a digital duty cycle value. A current sense circuit is coupled to at least one of the transistors and is configured to regularly sample a load current value. A comparator is coupled to the current sense circuit and is configured to compare the sampled load current value with a first threshold and to provide a respective comparator output signal. A regulator is configured to receive the comparator output signal and to calculate an updated digital duty cycle value.

Digital switching converter control

Methods, devices, and integrated circuits are disclosed for applying an active output voltage discharge for a buck-boost converter. One example is directed to a method of operating a buck-boost converter that comprises an inductor, an output capacitor, and an output. The method includes receiving an indication of an altered output voltage requirement in the buck-boost converter. The method further includes deactivating a control loop in the buck-boost converter. The method further includes applying an active discharge of voltage from the output capacitor through the inductor to ground, thereby altering the voltage at the output of the buck-boost converter from a first output voltage to a second output voltage that corresponds to the altered output voltage requirement. The method further includes reactivating the control loop.

Buck-boost converter with active output voltage discharge

Methods, devices, and circuits are disclosed delivering a first level of output current to one or more loads in a buck-boost converter comprising an inductor. The methods, devices, and circuits may further be disclosed applying, in response to an indication of an altered output current requirement to one or more loads in a buck-boost converter comprising an inductor, a change in a supplied reference voltage to one or more elements including a feedforward control element, wherein applying the change in the supplied reference voltage to the feedforward control element causes an adjustment of the output current from the first level to a second level corresponding to the altered current output requirement.

Feedforward circuit for fast analog dimming in LED drivers

A device can be used for detecting failures in an illumination device having a plurality of light emitting diodes connected in series. A first circuit node, a second circuit node, and a third circuit node interface the illumination device such that a voltage supplying the plurality of light emitting diodes is applied between the first and the second circuit node and a first fraction of the supply voltage drop is provided between the third and the second circuit node. An evaluation unit is coupled to the first circuit node, the second circuit node, and the third circuit node and configured to assess whether a voltage present at the third circuit node is within a pre-defined range of tolerance about a nominal value that is defined as a second fraction of the supply voltage present between the first and the second circuit node.

Failure detection for series of electrical loads

A driver circuit includes a buck converter associated with each LED chain for supplying a load current thereto. The buck converter receives an input voltage and is configured to provide a supply voltage to the associated LED chain such that the resulting load current of the LED chain matches at least approximately a predefined reference current value. The driver circuit further includes a switching converter that receives a driver supply voltage from a power supply and provides, as an output voltage, the input voltage for the buck converters. The switching converter is configured to provide an input voltage to the buck converters such that the maximum of the ratios between the input voltage and the supply voltages provided to the LED chains matches a predefined tolerance reference ratio.

Multi channel LED driver

In a circuit, a high side driver control circuit outputs gating signals to a high side driver of a synchronous converter responsive to a pulse width modulated input signal. A synchronous rectifier driver circuit outputs a gating signal to a synchronous rectifier of the synchronous converter responsive to the pulse width modulated input signal. An inhibit circuit inhibits the gating signal to the synchronous rectifier upon detection of a zero crossing condition. A circuit detects the zero crossing condition respective to comparing a measured value to a nominal value adjusted by a delta value. A duty cycle observer circuit determines the average duty cycle of the pulse width modulated input signal and varies the reference value.

Discontinuous conduction mode control circuit and method for synchronous converter

An output ripple control circuit and method for a PWM system uses a hysteresis threshold to clamp the output ripple of the PWM system such that the output ripple will not vary with the dc level of the output voltage, and therefore the output ripple control may be combined into any main loop technologies.

Output ripple control circuit and method for a PWM system

Disclosed is a method of determining a resonance frequency interval containing the resonance frequency of a rechargeable battery. The method comprises applying periodic current or voltage signals of different frequencies in succession to a battery cell of the battery. The method also comprises measuring of the temperatures of the battery cell occurring for the different frequencies. In addition, the method comprises comparing of the temperatures, and subsequent selection of an initial frequency of the different frequencies as a first interval value of the resonance frequency interval and a second frequency of the different frequencies as a second interval value of the resonance frequency interval based on the comparison of the temperatures.

Method of determining a frequency interval containing a resonance frequency of a rechargeable battery

A drive circuit is disclosed including a first feedback circuit designed to generate a first feedback signal from a first voltage to be controlled and a first reference voltage. The drive circuit further includes a signal converter designed to generate a second feedback signal from the first feedback signal such that the difference between the first feedback signal and a first amplitude value of a periodic signal approximately matches the difference between the second feedback signal and a second amplitude value of the periodic signal. The drive circuit also includes a first pulse width modulator which receives the first feedback signal and the periodic signal and generates the first pulse width-modulated signal. In addition the drive circuit includes a second pulse width modulator which receives the second feedback signal and the periodic signal and generates the second pulse width-modulated signal.

Drive circuit for two switching converter stages in a voltage converter

A method is disclosed for controlling a first transistor in a half-bridge circuit which also includes a second transistor. The transistors can be controlled by applying drive voltages to their gates. During a switch-off operation of the second transistor, the amplitude of the drive voltage of the second transistor is compared with a first threshold value and a second threshold value. A switch-on operation for the first transistor is started following a specified first period which begins at a first time when the drive voltage of the second transistor undershoots the first threshold value. The first threshold value is set in accordance with a second period which begins at a second time when the amplitude of the drive voltage of the second transistor undershoots the second threshold value. The second period ends at another time when the first transistor adopts a specified initial operating state during the switch-on operation.

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Padua, Italy

Giovanni Capodivacca