This application relates to methods and apparatus for driving a transducer with switching drivers. A switching driver has first and second supply node for receiving supply voltages and includes an output bridge stage, a capacitor and a network of switches. The network of switches is operable in different switch states to provide different switching voltages to the output bridge stage. A controller is configured to control the switch state of the network of switches and a duty cycle of output switches of the output bridge stage based on an input signal to generate an output signal for driving the transducer.

To prevent an output of an intermediate potential by suppressing sneaking of a current from a signal line to a power line at the time of disconnection of a power supply. A control circuit which receives a power supply voltage from a power line L11 and outputs an output signal to a signal line L12 includes: a load R11 which is provided between the power line and the signal line; a first transistor P11 which is provided between the load and the signal line; a second transistor P12 which is provided between a well of the first transistor and the power line; and a gate control circuit 15 which connects a gate terminal of the first transistor and a gate terminal of the second transistor to the signal line and turns off the first transistor and the second transistor, at the time of disconnection of a power supply.

An apparatus is provided which comprises: a power gate device coupled to a gated power supply node and an ungated power supply node; and a control circuitry coupled to the power gate device, wherein the control circuitry is to turn on the power gate device by providing at least two bias voltages separated in time to gradually turn on the power gate device.

The present invention concerns a device for controlling the switching of a first and a second power semiconductor switches providing current to a load in a half bridge configuration. The device comprises: means for obtaining a first current value through the first switch or the load just before the switching of the first switch from conducting to non-conducting state, means for limiting the current through the second switch during the switching of the second switch from non-conducting to conducting state using the obtained first current value, by modifying the gate signal of the second switch, means for obtaining a second current value through the second switch or the load just before the switching of the second switch from conducting to non-conducting state, means for limiting the current through the first switch during the switching of the first switch from non-conducting to conducting state using the obtained second current value by modifying the gate signal of the first switch.

A charge recovery driver is for a pair of loads, and includes first and second output nodes coupled to a pair of loads. During an initial phase, the first output node is grounded and the second output node is tied to the supply voltage. During a first phase, the first output node is coupled to the first tank capacitor and the second output node is coupled to the second tank capacitor. During a second phase, the first and second output nodes are coupled to one another. During a third phase, the second output node is coupled to the first tank capacitor and the first output node is coupled to the second tank capacitor. During a fourth phase, the first output node is coupled to the supply voltage and the second output node is coupled to ground. The third, second, and first phases are then repeated in that order.

A driving device of a semiconductor switch includes a semiconductor switch configured to perform a switching operation by a gate driving voltage, and transfer a main power connected to a first switch terminal, to a load connected to a second switch terminal; a control signal generation circuit configured to detect a change in a control signal input power and generate and output a corresponding control signal, based on a lower negative voltage between negative voltages of the main power and the control signal input power; a control signal detection circuit configured to detect the control signal and output a corresponding driving control signal; a gate driving voltage generation circuit configured to be driven by the driving control signal and output the gate driving voltage; and an internal power generation circuit configured to be supplied with the main power, and generate a power supply voltage.

Embodiments include a power conversion circuit comprising first and second semiconductor switches, and a drive circuit configured to create a period of operational overlap for the first and second switches by setting a gate voltage of the first switch to an intermediate value above a threshold voltage of the first switch, during turn-on and turn-off operations of the second switch. Embodiments also include a method of operating first and second semiconductor devices, comprising: reducing a gate voltage of the first device to an intermediate value above a threshold voltage while the second device is off; turning off the first device after the second device is on; increasing the gate voltage of the first device to the intermediate value while the second device is on; and fully turning on the first device after the second device is off.

Described are various techniques that can minimize the use of high-voltage devices in a unity-gain buffer that can be used in a high voltage application, while providing a circuit that generates an output that is an accurately buffered version of the input.

An oscillator assembly includes a scribe seal, an oscillator circuit, and a calibration circuit. The oscillator circuit includes an output. The calibration circuit is coupled to the oscillator circuit. The calibration circuit includes a reference frequency terminal, a conductor coupled to the reference frequency terminal, and an oscillator input terminal. The conductor extends to an edge of the oscillator circuit assembly and penetrates the scribe seal. The oscillator input terminal is coupled to the output of the oscillator circuit.

An oscillator assembly includes a scribe seal, an oscillator circuit, and a calibration circuit. The oscillator circuit includes an output. The calibration circuit is coupled to the oscillator circuit. The calibration circuit includes a reference frequency terminal, a conductor coupled to the reference frequency terminal, and an oscillator input terminal. The conductor extends to an edge of the oscillator circuit assembly and penetrates the scribe seal. The oscillator input terminal is coupled to the output of the oscillator circuit.