Dialog Semiconductor (uk) Limited

Dialog Semiconductor Gmbh

Tridonic Gmbh Co. Kg

Nebojsa Jelaca

Horst Knoedgen

Christoph Nagl

Stefan Zudrell-Koch

Ambreesh Bhattad

Frank Kronmueller

Julian Tyrrell

Gary Hague

Markus Mayrhofer

Kun Yang

Jung Woo Choi

Sander Heuvelmans

Dirk Dworatzek

An electronic circuit provided with a III/V semiconductor domain, and a method of operating such a circuit is presented. In particular, the present application relates to electronic circuit based on a Gallium Nitride (GaN) semiconductor. GaN components must be controlled in a way that ensures proper operation over a wide variation of GaN parameters. There is a circuit comprising a first domain coupled to a second domain, the first domain being based on a III/V semiconductor; wherein the first domain comprises a first component and a second component. The second component being representative of an electrical characteristic of the first component. The second domain contains a sensor adapted to sense an electrical quantity of the second component and an input generator coupled to the sensor. The input generator is adapted to provide at least one input, based on the electrical quantity, to the first domain.

Circuit based on a III/V semiconductor and a method of operating the same

A high-voltage power converter with a high-side switch coupled with a high-voltage input and a high-side switch control coupled with the high-side switch are presented. The high-side switch control drives the high-side switch on and off. There is a low-side switch coupled via an output node to the high-side switch. The low-side switch is on when the high-side switch is off and vice versa. A supply capacitor is coupled with a low-voltage supply terminal. The high-side switch control to provides a supply voltage for the high-side switch control. A communication module is coupled with the high-side switch control to provide a bidirectional communication between the high-side switch control and a control system that operates in a low-voltage domain, wherein the communication to and from the high-side switch control is enabled when the low-side switch is on and the high-side switch is off.

Bidirectional signaling method for high-voltage floating circuits

The present document describes a level-shifter circuit and method to transmit data from a high-voltage domain to a low-voltage domain. The level-shifter circuit has a first current path with a first current control unit to set a first current based on a high-voltage data signal in the high-voltage domain; and a second current path with a second current control unit to set a second current based on the high-voltage data signal. Furthermore, the circuit has an isolation unit to transfer the first current and the second current from the high-voltage domain to the low-voltage domain; and a current comparator unit to compare the first current with the second current to provide a low-voltage data signal in the low-voltage domain, which corresponds to the high-voltage data signal.

Circuit and method for ultra-high-voltage to low-voltage level shifting

A circuit for operating a transistor device that acts as a switch is presented. The circuit includes the transistor device and a control circuit coupled to a gate of the transistor device. The control circuit is adapted to selectively apply at least a first voltage level, a second voltage level, and a third voltage level to the gate of the transistor device, wherein the first, second, and third voltage levels are distinct voltage levels. The disclosure further relates to a method of operating a transistor device that acts as a switch. The proposed circuit provides additional gate voltages, by contrast to conventional two-level gate drivers. By appropriate choice of the additional gate voltages, reverse mode conductance losses of the transistor device can be reduced and/or to the Safe Operating Area (SOA) of the transistor device can be improved.

Multi-level gate control for transistor devices

An overvoltage protection circuit for a transistor device is presented. The overvoltage protection circuit comprises a first pin coupled to a gate terminal of the transistor device, an electrostatic discharge protection circuit coupled between a second pin and a source terminal of the transistor device, a first diode coupled between the first pin and the second pin, and a second diode coupled in parallel to the first diode between the first pin and the second pin. The forward direction of the first diode is opposite to the forward direction of the second diode. In addition, A method of measuring a gate leakage current of a transistor device and a method of bonding a transistor device coupled to such an overvoltage protection circuit are presented.

Overvoltage protection of transistor devices

A half bridge circuit and a method for its operation are presented. The half bridge circuit contains a high-side switch, a latch for providing a drive signal for the high-side switch, a first transistor device acting as a level shifter for shifting a voltage level at an input of the latch. The first transistor device is coupled between a supply voltage level and ground, and the voltage level at the input of the latch is shifted in accordance with a current that flows through the first transistor device. A second transistor device is coupled between the supply voltage level and ground, in parallel to the first transistor device. There is a current mirror for mirroring a current that flows through the second transistor device. There is a circuit path for feeding the mirrored current to an intermediate node between the supply voltage level and the first transistor device.

Compensation of level-shift capacitance

A circuit for driving a power switch is presented. The circuit includes a first power switch coupled to a second power switch via a switching node and a driver coupled to the first power switch, where the driver contains an energy storing element coupled to the switching node. The circuit also contains a sensor to sense an electrical parameter of the driver and a charger coupled to the sensor. The charger provides a charge current to charge the energy storage element, and to control the charge current based on the electrical parameter. In particular, a circuit for driving a power switch based on a III/V semiconductor is presented. In addition, a method of powering a power switch driver is presented. The method includes sensing an electrical parameter of the driver and adjusting a current to charge the energy storing element based on the electrical parameter.

Circuit for driving a power switch

A method and apparatus for limiting or preventing electromagnetic interferences in a switching converter are presented. In particular, a power circuit provided with an active electromagnetic interference filter is presented. There is an electromagnetic interference EMI reduction circuit for use with a switching converter. This EMI reduction circuit has a current source and is adapted to regulate a voltage across the current source to provide a current having a constant average value. The switching converter is adapted to provide a converter current, and the current source constant average value may be substantially equal to an average value of the converter current. The circuit has a variable resistance; and an adjuster adapted to adjust the variable resistance based on the converter current. The adjuster may have a comparator, which is adapted to compare a voltage value at a terminal of a transistor switch, and a reference value.

Apparatus and method for limiting electromagnetic interferences in a switching converter

A circuit and method for regulating an internal power supply of a switching converter is presented. A switching converter with a depletion mode power switch coupled to an enhancement mode power switch via a switching node and an energy storing element coupled to the depletion mode power switch is provided. The energy storing element may be adapted to provide energy to the switching converter. For instance, the energy storing element may be a capacitor. Optionally, the switching converter may comprise an inductor coupled to the depletion mode transistor, the inductor being adapted to provide an inductor current.

System and method for powering a switching converter

A method and apparatus for driving a power stage is presented. In particular, the power stage is a half-bridge. In the method, there is a first power switch coupled to a second power switch via a switching node. The method steps include sensing a first control-terminal voltage of one of the first power switch and the second power switch and turning on the first power switch based on the first control-terminal voltage and sensing a second control-terminal voltage of one of the first power switch and the second power switch and turning on the second power switch based on the second control-terminal voltage. Optionally, the first power switch is turned on when the first control-terminal voltage has reached a first threshold value, and the second power switch is turned on when the second control-terminal voltage has reached a second threshold value.

Apparatus and method for driving a power stage

An once a channel voltage exceeds a threshold, when the transistor is in an OFF state. This is over-voltage protection circuit for a transistor is presented. This circuit acts to switch on the transistor achieved with internal components which are integrated with the transistor, avoiding the need for external diodes or Zener structures. The circuit has a transistor with a control terminal, a first current carrying terminal and a second current carrying terminal. The over-voltage protection circuit has a level shifter arranged to feed back a level-shifted version of a channel voltage between said first and second current carrying terminals to the control terminal. The level shifter allows the switching threshold voltage of the transistor to be crossed when a predetermined value of the channel voltage is crossed.

Over voltage protection of a transistor device

A converter and a method of operating a switching converter in a low power mode are presented. The invention relates to a III/V semiconductor switching converter. A switching converter contains a first power switch coupled to a second power switch via a switching node. There is an inductor coupled to the switching node, and a clamp circuit containing a third power switch is coupled in parallel to the first power switch. The switching converter is adapted to turn the first power switch off and to enable control of the third power switch upon identifying that the switching converter provides a low level of power.

Switching converter with power level selection

A power efficient method and system for ensuring a reliable operation of dimmers in conjunction with solid state lighting devices such as LED or OLED assemblies is presented. A controller for a driver circuit of a solid state light bulb assembly is described. The solid state light bulb assembly comprises a solid state light source. The driver circuit comprises a switched-mode power converter. The controller is configured to receive an input voltage indicative of a mains electricity supply submitted to a dimmer; to determine that the dimmer is in an off-phase, based on the input voltage; and, if it is determined that the dimmer is in an off-phase, to generate a control signal for the switched-mode power converter to operate the switched-mode power converter in a switched mode for discharging one or more capacitances at an input of the switched-mode power converter.

Powerless bleeder

A controller for a driver circuit of a solid state lighting (SSL) device is described. The driver circuit comprises a power converter to transfer energy from AC mains voltage to the SSL device. The controller determines a dim level for the SSL device. The controller also determines a synchronization signal by comparing a voltage derived from the input voltage with a pre-determined threshold. The controller determines a sequence of PWM pulses based on the synchronization signal. The controller operates the power converter in a first operation mode for supplying energy to the SSL device at a first energy level within the sequence of PWM pulses, and operates the power converter in a second operation mode in between the PWM pulses. The second energy level is lower than the first energy level and the first energy level and/or a width of the PWM pulses depend on the dim level.

Accurate mains time-base for LED light driver

Driver circuits which reduce or remove flicker of solid state lighting SSL devices, notably at relatively low dimming levels are presented. The driver circuit comprises a power converter to transfer energy from an input of the driver circuit to the SSL device. The energy at the input is derived from an AC mains voltage at a mains frequency. A controller determines a dim level for the SSL device. and operates the power converter continuously in a first operation mode for supplying energy to the SSL device at a first energy level, if the dim level is above a pre-determined dim level threshold. The controller operates the power converter in the first operation mode at a time duration of PWM pulses, and operates the power converter in a second operation mode at a time duration in-between the PWM pulses, if the dim level is below the pre-determined dim level threshold.

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Nebojsa Jelaca