Supertex, Inc.

Microchip Technology Inc.

Monolithic Power Systems, Inc.

Supertax, Inc.

Jimes Lei

James Terrell Walker

Isaac Ko

Scott Lynch

Ka Wai Ho

Wan Tim Chan

Ching Chu

Benedict C K Choy

Kee Chee Tiew

Roshanak Aflatouni

James Michael Oliver Jenkins

Described herein are multiple designs for an improved analog switch for use in transmitting high voltage signals without using high voltage power supplies for the switch. The analog switches are able to pass and block input signals in the approximate range of &#x2212;100 V to +100 V. The use of translinear loops and a bootstrap configuration results in a constant on-resistance of the symmetrical switches and matches the conductance of each analog switch to the transconductance of an NMOS transistor, which can be easily stabilized with a constant gbiasing scheme. In certain embodiments, a shunt termination (T-switch) configuration is used for better off-isolation, and each of the symmetrical switches has its own translinear loop and thus flexibility of on-resistance and termination voltage.

Analog switch for transmitting high voltage signals without utilizing high voltage power supplies

Described herein are multiple designs for an improved analog switch for use in transmitting high voltage signals without using high voltage power supplies for the switch. The analog switches are able to pass and block input signals in the approximate range of &#x2212;100V to +100V. The use of translinear loops and a bootstrap configuration results in a constant on-resistance of the symmetrical switches and matches the conductance of each analog switch to the transconductance of an NMOS transistor, which can be easily stabilized with a constant gbiasing scheme. In certain embodiments, a shunt termination (T-switch) configuration is used for better off-isolation, and each of the symmetrical switches has its own translinear loop and thus flexibility of on-resistance and termination voltage.

An electrical waveform generating circuit has a pair of Pulse Amplitude Controlled Switching Current Sources (PACS). A gate pulse driver circuit is coupled to an input of each of the pair of PACS for sending gate pulses for driving the pair of PACS. A digital-to-analog converter (DAC) circuit is coupled to the gate pulse driver circuit for controlling amplitudes of the gate pulses. A transducer is coupled to the PACS.

Pulse amplitude controlled current source for ultrasound transmit beamformer and method thereof

A high voltage analog switch can be used in medical ultrasound applications. The high voltage analog switch can pass high voltage transducer excitation signals without necessarily having any high voltage power supplies. The high voltage analog switch can include three output switches, with one of the output switches having a clamp circuit for ensuring that transistors of an output switch on an input end of the high voltage analog switch remain OFF when the high voltage analog switch is OFF.

High voltage analog switch

A switching linear amplifier has a DC-DC converter to increase a low input DC voltage to a first high voltage DC. A high voltage high frequency inverter is coupled to the DC-DC converter to generate high voltage pulses. A multistage voltage multiplier is coupled to the high voltage high frequency inverter to generate a second high voltage DC. A controlled charge and discharge circuit is coupled to the multistage voltage multiplier to drive a capacitive load.

High voltage switching linear amplifier and method therefor

An integrated single channel or multi-channel ultrasound transmitter that minimizes the number of input connections to a controller such as an FPGA, field programmable gate array, or a custom integrated circuit in an ultrasound system. The method is accomplished by integrating, in low voltage logic, a means to store and or program the patterns required for the transmitter output. The number of logic input connections can be further reduced by further integrating, in low voltage logic, programmable individual time delays and frequency divider for each transmitter output.

Low pin count high voltage ultrasound transmitter and method therefor

A 5 Ringer Equivalent Number (REN) ringer circuit has a wave generator. A flip-flop is coupled to the wave generator and has a non-inverting and an inverting output. A high voltage level translator is coupled to each of the non-inverting and the inverting outputs of the flip-flop. A source follower buffer is coupled to an output of each of the high voltage level translators.

5 ringer equivalent number (REN) ringer circuit using a high voltage level translator and a source follower buffer and method therefor

A two terminal transmit receive device passes small analog signals with a constant low resistance value to the input of a low noise, low voltage receiver amplifier and can protect the input against the high voltage transmit signals in ultrasound applications without the aid of any power supplies. The device uses depletion-mode transistors that are normally on to pass small analog signal and a voltage detection circuit that quickly turns off the depletion-mode transistors when the presence of high voltage is detected.

High voltage transmit/receive switch and method therefor

An electroactive lens driver comprises a voltage generator generating a high alternating current voltage signal for application to an electroactive lens in response to a low direct current voltage signal. The voltage generator does not include an inductor or a transformer.

Inductorless electroactive lens driver and system

A high speed logic signal level shifter is comprised of: a logic signal buffer for receiving logic signal information and having true and complement state differential outputs; a binary flip-flop circuit with set and reset inputs; a first coupling capacitor connected from the true buffer output to the set input of the binary flip-flop circuit; and a second coupling capacitor connected from the complement buffer output to the reset input of the binary flip-flop circuit. The high speed logic signal level shifter transfers a fast logic signal across a high voltage difference by making use of rapid voltage changes transmitted through small capacitors. The signal changes carried by the capacitors are about 10 times faster than any expected voltage transient on VPP or VNN. Furthermore, the differential coupling circuit is used to provide enhanced protection against undesired circuit switching during supply voltage changes.

High-speed logic signal level shifter

An EL driver circuit has a full H-bridge circuit. A boost converter is coupled to the full H-bridge circuit. The boost converter is pulse width modulated to generate a gradual increase in voltage to be applied to the full H-bridge circuit to drive an EL lamp.

Low noise electroluminescent lamp (EL) driver and method therefor

A circuit for transmitting logic signals across a high voltage barrier has a logic signal buffer with true and complement state differential outputs. A binary flip-flop with set and reset inputs is further provided. A first coupling capacitor is coupled to the true buffer output and to the set input of the binary flip-flop. A second coupling capacitor is coupled to the complement buffer output and to the reset input of the binary flip-flop circuit.

High speed logic level shifter

A inductorless method and apparatus for driving electroluminescent (EL) panels enables fabrication of an integrated circuit that provides a complete EL panel driver solution in one package. The high voltage required to drive the EL panel is generated by a plurality of charge pump circuits. A multi-stage charge pump may be used to provide a high voltage power supply that does not require an external capacitor to store energy for the power supply.

Inductorless method and apparatus for driving electroluminescent panels

A low noise method and apparatus for driving electroluminescent (EL) panels provides reduction in EL panel noise, and in the preferred embodiment, voltage compensation as the EL panel ages. The output of a high voltage power supply is applied to the EL panel through a circuit having an optimized time-constant, producing a waveform that reduces EL panel vibration. Additionally, if the time constant is derived in part from the capacitance of the EL panel, the time constant may be chosen such that aging of the EL panel maintains the time constant in the proper range to maintain noise reduction over the life of the panel and compensate for brightness reduction due to aging of the EL panel.

Low noise method and apparatus for driving electroluminescent panels

A device which rectifies and regulates high voltage alternating current without the use of transformers, large capacitive coupling circuits or high voltage linear regulators. The device includes a rectifier, a control circuit for sensing the output voltage of the rectifier and switching on and off the input power, a storage capacitor and a low voltage linear regulator. The control circuit, which incorporates a voltage sensing circuit and a switch, limits the output voltage of the rectifier as seen by the linear regulator.

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Milpitas, CA, United States of America

Jimes Lei