California Micro Devices Corp.

Analog Devices,inc.

Semiconductor Components Industries, LLC

Adam J Whitworth

Dominick L Richiuso

Michael Steward Evans

Anthony Gerard Russell

Jeffrey C Dunnihoo

Wenjiang Zeng

Chadwick N Marak

Ashok Kumar Chalaka

Faraj A Sherrima

Hassan B Shami

In a general aspect, a circuit can include a pass device configured to receive an input voltage and provide an output voltage. The circuit can further include a current sink coupled with a control terminal of the pass device, the current sink being configured to discharge the control terminal of the pass device to limit the output voltage in response to the input voltage exceeding a threshold voltage. The circuit can also include a switch coupled in series with the current sink, the switch being configured to enable the current sink in response to the input voltage exceeding the threshold voltage.

Voltage clamping circuit

There is provided a method of making two electrically separated inductors using deposition and wet-etching techniques, which inductors are formed by interwinding one of the inductors within the other inductor on the same planar level. In still another aspect of the invention, there is provided a method of making various levels inductors, each level having at least two electrically separated inductors, using deposition and wet-etching techniques. The inductors on each planar level are formed by interwinding one of the inductors within the other inductor, and then stacking these in a preferred manner. In still another aspect, there is provided a manner of connecting together inductors formed according to the above methods in order to achieve various inductor configurations.

High density planarized inductor and method of making the same

An apparatus and method is provided for optimizing LED driver efficiency. The present invention offers low cost solutions for powering LEDs while minimizing overall power dissipation in devices powered by a depletable power source. Low system cost is attained using a charge pump to increase LED drive voltage level and implementing combinations of drive techniques to overcome the inefficiency of the charge pump. A switch bypasses the charge pump when depletable power source output voltage is sufficient to directly drive an LED load. At certain output voltage levels, the switch can be opened causing the charge pump to boost drive voltage. The output voltage may also be PWM modulated to drive the LED load and, at some voltages, the depletable power source may drive the LED load directly. Efficiency levels of 90-97% are attainable.

Maximizing efficiency of battery-powered LED drivers

The present invention is directed to bidirectional buffer with slew rate control in at least one direction. The present invention is also directed to a method of bidirectionally transmitting signals with slew rate control in at least one direction.

Bidirectional buffer with slew rate control and method of bidirectionally transmitting signals with slew rate control

An active termination circuit for clamping a signal on a transmission line in an electronic device is described. The active termination circuit is configured to clamp the signal on the transmission line to one of a first reference voltage level and a second reference voltage level. In one embodiment, the active termination circuit includes a bottom clamping transistor coupled to a first potential having a bottom clamping transistor control node arranged for clamping the signal at about a first reference voltage. The active termination circuit also includes a top clamping transistor coupled to a second potential having a top clamping transistor control node arranged for clamping the signal at about a second reference voltage as well as an inverter unit coupling the transmission line to stabilizing capacitors for stabilizing control node voltages.

Method and apparatus for non-linear termination of a transmission line

An apparatus consisting of a single wire bond silicon sub-mount used to make an LED device which also has built-in ESD protection in the sub-mount. The single wire bond silicon sub-mount uses a pass-through interconnection between the topside of the sub-mount and the underside so that the LED chip mounted thereon is electrically coupled through the sub-mount to the anode.

Silicon sub-mount capable of single wire bonding and of providing ESD protection for light emitting diode devices

An active termination circuit for clamping a signal on a transmission line in an electronic device is described. The active termination circuit is configured to clamp the signal on the transmission line to one of a first reference voltage level and a second reference voltage level. The active termination circuit includes a bottom clamping transistor having a bottom clamping transistor first node coupled to a transmission line at a transmission line node, a bottom clamping transistor second node coupled to a first potential, and a bottom clamping transistor control node coupled to a first bias voltage supply. The circuit also includes a top clamping transistor having a top clamping transistor first node coupled to the transmission line at the transmission line node, a top clamping transistor second node coupled to a second potential, and a top clamping transistor control node coupled to a second bias voltage supply. The circuit further includes a variable current source arranged to provide bias current as needed to only one or the other of the first bias voltage supply and the second bias voltage supply based upon the state of an input signal on the transmission line.

An active termination circuit having a selective DC power consumption for clamping signals on a bus in an electronic device is described. The active termination circuit is configured to clamp the signals on the bus to one of a first reference voltage level and a second reference voltage level. In one embodiment, the active termination circuit includes bottom clamping transistors coupled to a first potential having bottom clamping transistor control nodes arranged for clamping the signal at about a first reference voltage. The active termination circuit also includes top clamping transistors coupled to a second potential having top clamping transistor control nodes arranged for clamping the signal at about a second reference voltage. The circuit also has a variable current supply coupled to said first threshold reference transistor and said second threshold reference transistor arranged to reduce the DC power consumption of the active termination circuit as needed.

Termination circuits and methods therefor

An active termination circuit for clamping a signal on a transmission line in an electronic device is described. The active termination circuit is configured to clamp the signal on the transmission line to one of a first reference voltage level and a second reference voltage level. In one embodiment, the active termination circuit includes a bottom clamping transistor coupled to a first potential having a bottom clamping transistor control node arranged for clamping the signal at about a first reference voltage. The active termination circuit also includes a top clamping transistor coupled to a second potential having a top clamping transistor control node arranged for clamping the signal at about a second reference voltage as well as stabilizing capacitors for stabilizing control node voltages.

An active termination circuit for clamping signals on a bus in an electronic device is described. The active termination circuit is configured to clamp the signals on the bus to one of a first reference voltage level and a second reference voltage level. In one embodiment, the active termination circuit includes bottom clamping transistors coupled to a first potential having bottom clamping transistor control nodes arranged for clamping the signal at about a first reference voltage. The active termination circuit also includes top clamping transistors coupled to a second potential having top clamping transistor control nodes arranged for clamping the signal at about a second reference voltage.

An active termination circuit having localized potential supplies for clamping a signal on a transmission line in an electronic device is described. The active termination circuit is configured to clamp the signal on the transmission line to one of a first reference voltage level and a second reference voltage level. In one embodiment, the active termination circuit includes a bottom clamping transistor coupled to a first localized potential having a bottom clamping transistor control node arranged for clamping the signal at about a first reference voltage. The active termination circuit also includes a top clamping transistor coupled to a second localized potential having a top clamping transistor control node arranged for clamping the signal at about a second reference voltage. Any voltage excursions at the first localized potential does not affect the first localized reference voltage, and vice versa and any voltage excursions at the second localized potential does not affect the second localized reference voltage, and vice versa.

An active termination circuit for clamping a signal on a transmission line in an electronic device is described. The active termination circuit is configured to clamp the signal on the transmission line to one of a first reference voltage level and a second reference voltage level. In one embodiment, the active termination circuit includes a bottom clamping transistor coupled to a first potential having a bottom clamping transistor control node arranged for clamping the signal at about a first reference voltage. The active termination circuit also includes a top clamping transistor coupled to a second potential having a top clamping transistor control node arranged for clamping the signal at about a second reference voltage.

An active termination circuit for clamping a signal on a transmission line in an electronic device in a tri-state mode is described. The active circuit includes a tri-state output buffer and a bottom clamping transistor coupled to GND and the tri-state output buffer having a bottom clamping transistor control node arranged for clamping the signal at about GND. A bottom threshold reference transistor coupled to a first reference voltage supply configured to supply a first reference voltage. The bottom threshold reference transistor provides a first bias voltage to the bottom clamping transistor control node that biases the bottom clamping transistor control node at about a first threshold voltage above GND where the first threshold voltage represents a threshold voltage of the bottom clamping transistor. A top clamping transistor coupled to VDD and the tri-state output buffer having a top clamping transistor control node arranged for clamping said signal at about VDD and a top threshold reference transistor coupled to a second reference voltage supply configured to supply a second reference voltage. The top threshold reference transistor provides a second bias voltage to the top clamping transistor control node that biases the top clamping transistor control node at about a second threshold voltage from VDD where the second threshold voltage represents a top clamping transistor threshold voltage.

Growing community of inventors

Sunnyvale, CA, United States of America

Adam J Whitworth