Abstract: An amplifier structure includes shield conductors that are provided spatially adjacent to elongated feedback signal lines that couple a feedback circuit to an amplifier input. The shield conductors are provided between the feedback signal lines and a ground plane, which interrupts a parasitic capacitance that otherwise would be established between the feedback signal line and ground. The shield conductors are electrically coupled to the amplifier's outputs which create a capacitance between the output terminal and the feedback signal line. In some embodiments, the capacitance generated between the output terminal and the feedback signal line can suffice as a capacitor in a feedback path of the amplifier and be contained in an integrated circuit die on which the amplifier is manufactured. Optionally, a structure may be provided that eliminates common mode signals on the feedback lines while simultaneously preserving the common mode signals on the amplifier output terminals.
Abstract: A quadrature demodulator preweights an input signal prior to mixing with in-phase and quadrature clock signals. In an implementation with discrete phase rotation, a series of weighting circuits may be arranged before or after a select circuit to select the amount of phase rotation. Various implementations may include ratioed current mirrors to perform the weighting function, a stacked arrangement of mixers, an H-bridge input stage, integrated mixers and select circuits, and/or selectable gain stages such as gm cells to perform the weighting function.
Abstract: An analog to digital converter comprising an Nth analog to digital converter and an N+1th analog to digital converter arranged in series such that a residue signal from the Nth analog to digital converter is provided as an input to the N+1th analog to digital converter, characterised in that a bandwidth control means is provided in a signal path for the residue signal and the bandwidth control means is controlled so as to have a first bandwidth during a first period following generation of a conversion result from the Nth analog to digital converter, and a second bandwidth less than the first bandwidth in a second period following the first period.
Type:
Application
Filed:
August 3, 2009
Publication date:
July 15, 2010
Applicant:
ANALOG DEVICES, INC.
Inventors:
Christopher Peter HURRELL, Colin G. LYDEN, Ronald A. KAPUSTA
Abstract: A method of forming a thick polysilicon layer for a MEMS inertial sensor includes forming a first amorphous polysilicon film on a substrate in an elevated temperature environment for a period of time such that a portion of the amorphous polysilicon film undergoes crystallization and grain growth at least near the substrate. The method also includes forming an oxide layer on the first amorphous polysilicon film, annealing the first amorphous polysilicon film in an environment of about 1100° C. or greater to produce a crystalline film, and removing the oxide layer. Lastly, the method includes forming a second amorphous polysilicon film on a surface of the crystalline polysilicon film in an elevated temperature environment for a period of time such that a portion of the second amorphous polysilicon film undergoes crystallization and grain growth at least near the surface of the crystalline polysilicon film.
Abstract: A transistor cell is provided that includes transistors arranged to turn on for different voltages applied to a control terminal of the transistor cell. The transistor cell can include a first transistor having a gate, a source, and a drain, and a second transistor having a gate, a source, and a drain, wherein the source of the second transistor is coupled to the source of the first transistor, and the drain of the second transistor is coupled to the drain of the first transistor. The transistor cell can further include a first resistor coupled between the gate of the first transistor and the gate of the second transistor. A frequency mixer is also provided that includes at least one transistor cell.
Abstract: A method of packaging an integrated circuit singulates a wafer to form an integrated circuit, positions the integrated circuit on a carrier, and passivates the integrated circuit after the positioning the integrated circuit on the carrier. At this point, the integrated circuit is secured to the carrier. The method also electrically connects the integrated circuit to a plurality of exposed conductors.
Abstract: Circuits and methods for reducing distortion in an amplified signal are disclosed. The circuits and methods may use multiple single-ended gain stages to produce multiple amplified signals. The amplified signals may be processed in combination to produce a resulting output signal having little, or no, distortion. The circuits may be implemented on a single chip as integrated circuits.
Type:
Grant
Filed:
March 21, 2008
Date of Patent:
July 6, 2010
Assignee:
Analog Devices, Inc.
Inventors:
Pavel Bretchko, Shuyun Zhang, Royal Gosser
Abstract: A reference voltage circuit which is less dependent on semiconductor process variations compared to bandgap based reference voltage circuits. The circuit comprises a first amplifier having an inverting input, a non-inverting input and an output. A current biasing circuit provides first and second PTAT currents, and a CTAT current. The CTAT current is equal in value to the second PTAT at a first predetermined temperature and opposite in polarity. A first load element is coupled to the non-inverting input of the first amplifier and arranged for receiving the first PTAT current such that a PTAT voltage is developed across the first load element. A feedback load element is coupled between the inverting input and the output of the amplifier for receiving the summation of the CTAT current and the second PTAT current.
Abstract: A measurement signal from a detector may have a complementary polarity. For example, an RF power detector may generate an output signal that decreases in magnitude in response to an increasing input signal. In one embodiment, the RF power detector may include a series of transconductance detector cells arranged to progressively turn off as the input signal becomes progressively larger.
Abstract: Compensating for wideband quadrature imbalance error by introducing inverse complex inputs to phase quadrature estimator filters to generate estimated quadrature distortion; summing estimator quadrature distortion with a delayed version of the actual complex input to obtain estimated quadrature output; comparing the output with the true output to obtain residual quadrature imbalance error; applying a least mean square to the inverse input and imbalance residual error to obtain an updated estimate of filter coefficients; updating the filter coefficients of the phase quadrature estimator; and updating the filter coefficients of a phase quadrature compensator with the filter coefficients of the phase quadrature estimator to obtain a quadrature output pre-compensated for quadrature imbalance error.
Abstract: Effective control of the common-mode level of amplifiers is obtained through control structures (both closed-loop and open-loop structures) which are directed to various amplifier functions such as the reduction of amplifier loading, accurate sensing of common-mode levels, mitigation of headroom restraints, and proper transistor biasing. This common-mode control is especially useful in multiplying analog-to-digital converters (MDACs) of signal processing systems.
Abstract: Disclosed is a micro-electro-mechanical switch, including a substrate having a gate connection, a source connection, a drain connection and a switch structure, coupled to the substrate. The switch structure includes a beam member, an anchor and a hinge. The beam member having a length sufficient to overhang both the gate connection and the drain connection. The anchor coupling the switch structure to the substrate, the anchor having a width. The hinge coupling the beam member to the anchor at a respective position along the anchor's length, the hinge to flex in response to a charge differential established between the gate and the beam member. The switch structure having gaps between the substrate and the anchor in regions proximate to the hinges.
Type:
Application
Filed:
December 18, 2008
Publication date:
June 24, 2010
Applicant:
Analog Devices, Inc.
Inventors:
Denis ELLIS, Padraig FITZGERALD, Jo-ey WONG, Raymond GOGGIN, Richard Tarik Gereon ECKL
Abstract: A microchip system has a package forming a hermetically sealed interior, and MEMS structure within the interior. The system also has a gas sensor for detecting the concentration of at least one of oxygen or hydrogen within the interior.
Abstract: The present invention relates to a semiconductor device including a substrate layer, a metal-oxide-semiconductor field-effect transistor (MOSFET), a backgate region, an isolation layer and a diode. The MOSFET includes a gate region, a source region and a drain region. The source and drain regions are embedded in the backgate region, which includes a voltage input terminal. The isolation layer is located between the backgate region and the substrate layer and has a doping type opposite that of the backgate region. The diode includes a first terminal connected to the isolation layer and a second terminal coupled to an isolation voltage source.
Abstract: A photodiode is formed in a recessed germanium (Ge) region in a silicon (Si) substrate. The Ge region may be fabricated by etching a hole through a passivation layer on the Si substrate and into the Si substrate and then growing Ge in the hole by a selective epitaxial process. The Ge appears to grow better selectively in the hole than on a Si or oxide surface. The Ge may grow up some or all of the passivation sidewall of the hole to conformally fill the hole and produce a recessed Ge region that is approximately flush with the surface of the substrate, without characteristic slanted sides of a mesa. The hole may be etched deep enough so the photodiode is thick enough to obtain good coupling efficiencies to vertical, free-space light entering the photodiode.
Abstract: The invention is directed to a protection circuit for protecting IC chips against ESD. An ESD protection circuit for an integrated circuit chip may comprise an isolated NMOS transistor, which may comprise an isolation region isolating a backgate from a substrate, and a first and second doped regions and a gate formed on the backgate. The ESD protection circuit may further comprise a first terminal to connect the isolation region to a first electrical node, and a second terminal to connect the second doped region to a second electrical node. The first electrical node may have a higher voltage level than the second electrical node, and the gate and backgate may be coupled to the second terminal.
Abstract: A system for converting digital signals into analog signals using sigma-delta modulation and includes a signed thermometer encoder for converting a plurality of signed binary data received at the encoder into a plurality of signed thermometer data and a rotational dynamic element matching (DEM) arrangement for receiving the plurality of signed binary data and the plurality of signed thermometer data. The rotational DEM arrangement further includes a first barrel shifter for receiving a positive thermometer data at a cycle, the first barrel shifter having a first pointer indicating a starting position of next positive thermometer data, and a second barrel shifter for receiving a negative thermometer data at a cycle, the second shifter having a second pointer indicating a starting position of next negative thermometer data, wherein the first pointer is circularly shifted as a function of positive binary data and the second pointer is circularly shifted as a function of negative binary data.
Type:
Application
Filed:
December 12, 2008
Publication date:
June 17, 2010
Applicant:
Analog Devices, Inc.
Inventors:
Khiem Quang NGUYEN, Abhishek BANDYOPADHYAY, Michael DETERMAN
Abstract: An analog amplifier includes at least one signal path. Each of the at least one signal path extends between an input and an output and includes a load device coupled to the output and a transistor coupled to the input. The analog amplifier further includes a dither current source selectively coupled to one of the at least one signal path. The dither current source is capable of supplying dither current to the load device of the selected signal path directly by bypassing the transistor of the selected signal path.
Abstract: An embodiment of the present invention may be directed to a multi channel imaging system. The multi channel imaging system may include an input for a light signal and a plurality of channel circuits. Each of the channel circuits may have an analog signal processing chain converting some portion of the light signal into to a digital representation, the plurality of channel circuits may operate in parallel. The multi channel imaging system may further comprise at least one dither circuit coupled to a point in at least one of the analog signal processing chains to add dither.
Abstract: Described is a die having photodetectors provided on a first surface thereof. The die includes an insulative shell member, a conductive shell member and a photodetector conductor. The insulative shell member extends around a periphery of the photodetector receptors and extending through a depth of the semiconductor die. The conductive shell member bridges the insulative shell member and extends through the depth of the semiconductor die. The photodetector conductors are provided on the first surface of the semiconductor die and electrically couple respective photodetectors with a corresponding conductive shell member. Also described is a process for making a semiconductor die and an integrated circuit structure.
Type:
Grant
Filed:
June 12, 2008
Date of Patent:
June 15, 2010
Assignee:
Analog Devices, Inc.
Inventors:
Shrenik A. Deliwala, Michael C Coln, Alain Valentin Guery