Method of fabricating a bipolar transistor using selective epitaxially grown SiGe base layer
Granted: March 4, 2004
Application Number:
20040043576
Embodiments of a bipolar transistor are disclosed, along with methods for making the transistor. An exemplary transistor includes a collector region in a semiconductor substrate, a base layer overlying the collector region and bound by a field oxide layer, a dielectric isolation layer overlying the base layer, and an emitter structure overlying the dielectric isolation layer and contacting the base layer through a central aperture in the dielectric layer. The transistor may be a…
Tandem Si-Ge solar cell with improved conversion efficiency
Granted: June 26, 2003
Application Number:
20030116187
P-type and n-type regions are defined in the first surface of a substrate upon which is formed an epitaxial layer of preferably Si—Ge material, preferably capped by Si material. During epitaxy formation, dopant in the defined regions diffuses down to form p-type and n-type junctions in the Si material, and diffuses up to form p-type and n-type junctions in the Si—Ge epitaxial material. Si junctions are buried beneath the surface and are surface recombination velocity effects…
Voltage-controlled variable duty-cycle oscillator
Granted: June 26, 2003
Application Number:
20030117222
A voltage-controlled variable duty-cycle oscillator includes a current generator whose current Iref mirrored in three one-shots that each include two pair of series-coupled MOS transistors and a timing capacitor. The timing capacitor is precharged to Vcc in the first two one-shots, and to a lesser voltage Vcon in the third one-shot. The oscillator also includes pre and a post-NOR-gate logic. Output signals from the two one-shots are coupled to the pre NOR-gate logic to generate an…
RING TOPOLOGY BASED VOLTAGE CONTROLLED OSCILLATOR
Granted: May 29, 2003
Application Number:
20030098747
A VCO includes N delay stages that each contribute 180°/N phase shift at the VCO frequency of interest and provide a tunable selection of at least a fast delay and a slow delay path. Each delay stage includes a delay interpolator that smoothly interpolates between the delay paths within the stage. Each delay stage is coupled to a bandpass frequency selective network that acts as a load and helps filter phase noise. Feedback from the Nth delay stage to the first delay stage is via a…
Method and apparatus for optimizing the accuracy of an electronic circuit
Granted: May 1, 2003
Application Number:
20030080759
The present invention provides an apparatus and method for improving the accuracy of circuits. The apparatus includes a replicate circuit and a trim determination circuit. The trim determination circuit includes a measurable circuit element and determines the state of the measurable element. The replicate circuit includes a replicate circuit element which has similar electrical characteristics as the measurable element, and is configured to aid in determining an adjustable test current.…
Apparatus and method for encoding and decoding signals
Granted: April 3, 2003
Application Number:
20030064684
The present invention provides an apparatus and method for encoding and/or decoding signals. The encoding apparatus includes a variable impedance being coupled with an encoder. The variable impedance establishes a select voltage at the encoder. The encoder is further coupled with an input signal, wherein the encoder generates a modulated output as dictated by the select voltage. The decoding apparatus includes an integrator, a comparator and at least a first variable impedance. The…
Output stage and method of enhancing output gain
Granted: September 5, 2002
Application Number:
20020121934
The present invention provides for an output stage which couples with an input stage and is configured to limit a reflection current which is reflected back into the input stage to enhanced an output voltage to drive a variety of loads. The present output stage limits the reflection current by compensating for at least one bias current at the input stage output. The output stage further reduced a quiescent current needed to maintain the output stage in an active state without adversely…
Universally stable output filter
Granted: June 13, 2002
Application Number:
20020070814
In accordance with the teachings of this invention a novel method and apparatus is taught which provides for the stabilizing of an output signal through an output circuit having a compensation circuit coupled with an output capacitor, such that the compensation circuit is configured to compensate for an equivalent series resistance of the output capacitor. The compensation circuit compensates for the equivalent series resistance by providing a shift in a phase of the output signal to…
Method and apparatus for providing thermal shutdown and current limiting protection
Granted: May 30, 2002
Application Number:
20020064008
The present invention provides an apparatus and method for preventing damage to a system due to runaway current and provides for the reactivation of the system. The shutdown and reactivation method and apparatus includes a driving circuit which supplies an output current to a load. If a runaway current condition occurs in the system the shutdown and reactivation apparatus is activated by triggering a shutdown signal which deactivates the driving circuit such that the output current is no…
