Analog Devices International Unlimited Company

Linear Technology Corporation

Jade Sky Technologies, Inc.

Analog Devices,inc.

Eugene Cheung

Joseph Adut

Gregory A Fung

Brian D Hamilton

Jeremy Wong

Talbott Mead Houk

David J Chen

Ronald Alan Kapusta

Shawn S Kuo

Leonard Shtargot

Jonathan Paolucci

Xu Tang

David C Tournatory

Joseph Duncan

A multi-stage transimpedance amplifier (TIA) with an adjustable input linear range is disclosed. The TIA includes a first stage, configured to convert a single-ended current signal from an optical sensor of a receiver signal chain to a single-ended voltage signal, and a second stage, configured to convert the single-ended voltage signal provided by the first stage to a differential signal. In such a TIA, the input linear range may be adjusted using a clamp that is programmable with an output offset current to keep the second stage of the TIA from overloading and to maintain a linear transfer function without compression.

Transimpedance amplifiers with adjustable input range

Techniques to achieve higher power/shorter pulses with a laser diode. By initially applying a static reverse bias across the laser diode, the laser diode can turn on at a larger inductor current. When the laser diode is initially reverse biased, depletion charge and diffusion charge can be populated before the laser diode will lase. This causes the laser diode to initially turn on at a larger inductor current, which will reduce the rise time, thereby achieving higher power/shorter pulses.

Laser diode driver circuit techniques

Differential clamp circuits configured to recirculate the current in one clamp, either low-side clamp or high-side clamp, from one output of a differential signal to the other output of the differential signal are disclosed. Differential clamp circuits described herein may be particularly suitable for providing programmable clamps at differential outputs of an ADC driver and may be particularly beneficial to implement clamps that are symmetrical around an ADC's input common-mode voltage. Some differential clamp circuit described herein may advantageously present a smaller capacitive load at each output, thus reducing bandwidth degradation of the output stage. Furthermore, differential clamp circuits described herein may operate with only one control voltage, making it easier to limit the output excursions symmetrically around the default common-mode voltage.

Differential clamp circuits with current recirculation

Methods and apparati for controlling bleed current (IBLEED) in a driver circuit () for a lighting device (). A method embodiment of the present invention comprises the steps of coupling a dimmer () to an input of the driver circuit (), and forcing the bleed current (IBLEED) to be inversely proportional to the time-averaged voltage (VLEDP) at said lighting device (). The dimmer () consumes power even when the lighting device () is not emitting light.

Control of bleed current in drivers for dimmable lighting devices

Methods and apparati for forcing the current through a load () in a variable DC electrical circuit to be proportional to the input voltage (V(in)). A circuit embodiment of the present invention comprises a source () of input AC; a rectifier () coupled to the input AC source (), said rectifier () producing a variable DC input voltage; coupled to the rectifier (), a load () having a variable direct current flowing therethrough; and means (-) for forcing the current through the load () to be proportional to the variable DC input voltage.

Load driver with integrated power factor correction

An analog control circuit is coupled to an apparatus having a variable characteristic over an operating range. A sensing circuit is coupled to the apparatus and the control circuit during the range of operation of the apparatus and is operative to sense the variable characteristic. The operating parameter of the apparatus is controlled to be set at a level corresponding to a prescribed criterion, which may be a maximum or minimum, of the characteristic sensed over the range of operation.

System and method for tracking a variable characteristic through a range of operation

Pulse width modulation of the connection of a load output terminal to a power supply terminal is effected. In response to a first level of the pulse width modulated signal, the load is disconnected from the power supply terminal, steady-state load voltage is preserved on a capacitor connected between a load output terminal and a power supply terminal, and steady-state load current information is held on a capacitor within the feedback loop. In response to a second level of the pulse width modulated signal, the load is reconnected to the power supply terminal, and load voltage and current instantaneously resume at their correct steady-state values.

Growing community of inventors

Fremont, CA, United States of America

Eugene Cheung