Abstract: Circuits and methods that control a rate of change of a drain voltage as a function of time in a transistor are disclosed. In one aspect, the circuit includes a transistor having a gate terminal that controls operation of the transistor, and a control circuit coupled to the gate terminal and arranged to change a voltage at the gate terminal at a first rate of voltage with respect to time from a first voltage to a first intermediate voltage, and further arranged to change the voltage at the gate terminal at a second rate of voltage with respect to time from the first intermediate voltage to a second intermediate voltage, where the first rate is different than the second rate.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: Systems and methods for a GaN-based motor drive circuit using synchronous rectification is disclosed. In one aspect, a method of operating a motor drive circuit includes providing a half-bridge circuit including a high-side GaN switch and a low-side GaN switch coupled in series at an output node, providing a motor coupled to the output node, turning on the high-side GaN switch such that a first current flows through the motor, turning off the high-side GaN switch, turning on the low-side GaN switch when a voltage at the output node drops below a predetermined threshold voltage, sensing, using a sense device coupled to the low-side GaN switch, a magnitude of a second current that flows through the low-side GaN switch, and turning off the low-side GaN switch when the magnitude of the second current drops below a predetermined threshold current.

Abstract: Control techniques and circuits for resonant power converters and other power converters are described. Control of power converters based on more than one control parameter can provide improved efficiency over a wide operating range. A resonant power converter may have its switching frequency controlled within a narrow band to improve efficiency.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: A circuit is disclosed. The circuit includes a current detecting FET, configured to generate a current signal indicative of the value of the current flowing therethrough, an operational transconductance amplifier (OTA) configured to output a current in response to the voltage of the current signal, and a resistor configured to receive the current and to generate a voltage in response to the received current, where the generated voltage is indicative of the value of the current flowing through the current detecting FET. The current detecting FET is configured to become nonconductive in response to the generated voltage indicating that the current flowing through the current detecting FET is greater than a threshold.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: Turn-off circuits. In one aspect, the turn-off circuit includes a transistor having a gate terminal, a source terminal and a drain terminal, a first pull-down circuit connected to the gate terminal, a second pull-down circuit connected to the gate terminal, and a third pull-down circuit connected to the gate terminal. In another aspect, the first, the second and the third pull-down circuits are arranged to cause a turn off of the transistor by changing a voltage at the gate terminal at a first rate of voltage with respect to time from an on-state voltage to a first intermediate voltage, and from the first intermediate voltage to a second intermediate voltage at a second rate of voltage with respect to time, and from the second intermediate voltage to an off-state voltage at a third rate of voltage with respect to time, wherein the first rate is higher than the second rate.

Abstract: Circuits and methods that control a rate of change of a drain voltage as a function of time in a transistor are disclosed. In one aspect, the circuit includes a transistor having a gate terminal that controls operation of the transistor, and a control circuit coupled to the gate terminal and arranged to change a voltage at the gate terminal at a first rate of voltage with respect to time from a first voltage to a first intermediate voltage, and further arranged to change the voltage at the gate terminal at a second rate of voltage with respect to time from the first intermediate voltage to a second intermediate voltage, where the first rate is different than the second rate.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: A circuit is disclosed. The circuit includes a current detecting FET, configured to generate a current signal indicative of the value of the current flowing therethrough, an operational transconductance amplifier (OTA) configured to output a current in response to the voltage of the current signal, and a resistor configured to receive the current and to generate a voltage in response to the received current, where the generated voltage is indicative of the value of the current flowing through the current detecting FET. The current detecting FET is configured to become nonconductive in response to the generated voltage indicating that the current flowing through the current detecting FET is greater than a threshold.

Abstract: A power module includes a power converter having a controller configured to control the power converter. The controller is configured to control the power converter using feedback for a first load on the power converter, and to allow the power converter to operate without controlling the power converter using the feedback for second load on the power converter higher than the first load.

Abstract: A circuit is disclosed. The circuit includes a current detecting FET, configured to generate a current signal indicative of the value of the current flowing therethrough, an operational transconductance amplifier (OTA) configured to output a current in response to the voltage of the current signal, and a resistor configured to receive the current and to generate a voltage in response to the received current, where the generated voltage is indicative of the value of the current flowing through the current detecting FET. The current detecting FET is configured to become nonconductive in response to the generated voltage indicating that the current flowing through the current detecting FET is greater than a threshold.

Abstract: Control techniques and circuits for resonant power converters and other power converters are described. Control of power converters based on more than one control parameter can provide improved efficiency over a wide operating range. A resonant power converter may have its switching frequency controlled within a narrow band to improve efficiency.

Abstract: A semiconductor device includes at least a first transistor including at least a second level metal layer (second metal layer) above a first level metal layer coupled by a source contact to a source region doped with a first dopant type. The second level metal layer is coupled by a drain contact to a drain region doped with the first dopant type. A gate stack is between the source region and drain region having the second level metal layer coupled by a contact thereto. The second level metal layer is coupled by a contact to a first isolation region doped with the second dopant type. The source region and drain region are within the first isolation region. A second isolation region doped with the first dopant type encloses the first isolation region, and is not coupled to the second level metal layer so that it electrically floats.

Abstract: A current detecting GaN FET is disclosed. The current detecting GaN FET includes a first GaN switch having a first gate, a first drain, a first source, and a first field plate. The current detecting GaN FET also includes a second GaN switch having a second gate, a second drain, a second source, and a second field plate. The current detecting GaN FET also includes a resistor. The first and second gates are electrically connected, the first and second drains are electrically connected, and the resistor is connected between the first and second sources.

Abstract: Control techniques and circuits for resonant power converters and other power converters are described. Control of power converters based on more than one control parameter can provide improved efficiency over a wide operating range. A resonant power converter may have its switching frequency controlled within a narrow band to improve efficiency.

Abstract: A half bridge circuit is disclosed. The circuit includes low side and high side power switches selectively conductive according to one or more control signals. The circuit also includes a low side power switch driver, configured to control the conductivity state of the low side power switch, and a high side power switch driver, configured to control the conductivity state of the high side power switch. The circuit also includes a controller configured to generate the one or more control signals, a high side slew detect circuit configured to prevent the high side power switch driver from causing the high side power switch to be conductive while the voltage at the switch node is increasing, and a low side slew detect circuit configured to prevent the low side power switch driver from causing the low side power switch to be conductive while the voltage at the switch node is decreasing.

Abstract: A current detecting GaN FET is disclosed. The current detecting GaN FET includes a first GaN switch having a first gate, a first drain, a first source, and a first field plate. The current detecting GaN FET also includes a second GaN switch having a second gate, a second drain, a second source, and a second field plate. The current detecting GaN FET also includes a resistor. The first and second gates are electrically connected, the first and second drains are electrically connected, and the resistor is connected between the first and second sources.

Abstract: A circuit is disclosed. The circuit includes a current detecting FET, configured to generate a current signal indicative of the value of the current flowing therethrough, an operational transconductance amplifier (OTA) configured to output a current in response to the voltage of the current signal, and a resistor configured to receive the current and to generate a voltage in response to the received current, where the generated voltage is indicative of the value of the current flowing through the current detecting FET. The current detecting FET is configured to become nonconductive in response to the generated voltage indicating that the current flowing through the current detecting FET is greater than a threshold.