Patent classifications
H03G1/00
Offset compensated differential amplifier and calibration circuit providing increased linear range and granularity of offset compensation and related method
An offset compensated differential amplifier employing a multi-tan h circuit comprising differential pairs coupled in parallel to compensate for an offset voltage of the output voltage in the offset compensation calibration mode is disclosed. The differential pairs each include a compensation transistor coupled to the positive internal node and a reference transistor coupled to the negative internal node. Each compensation transistor receives the compensation control voltage and each reference transistor receives a different reference voltage. The multi-tan h circuit generates an offset compensation voltage on the positive and negative internal nodes based on a difference between the compensation control voltage and the different reference voltages. The multi-tan h circuit comprises a larger linear range than a hyperbolic tangent current transfer function of a single differential pair. The offset compensated differential amplifier provides offset compensation with improved linearity and a finer granularity compared to a conventional differential amplifier.
Power control based on packet type
Techniques for controlling one or more audio amplifiers in or associated with a device coupled on a local area network are disclosed. An example playback device includes a processor, an amplifier, a network interface, and a memory. The memory includes a software module that, when executed by the processor, causes the playback device to: operate in a first power mode in which the amplifier consumes a first amount of power; while operating in the first power mode, determine that a defined time has passed since receiving, via the network interface, a specified type of data packet; and based on determining that the defined time has passed since receiving the specified type of data packet, transition from operating in the first power mode to operate in a second power mode in which the amplifier consumes a second amount of power, wherein the first amount of power is greater than the second amount of power.
Optimized multi gain LNA enabling low current and high linearity including highly linear active bypass
An LNA having a plurality of paths, each of which can be controlled independently to achieve a gain mode. Each path includes at least an input FET and an output FET coupled in series. A gate of the output FET is controlled to set the gain of the LNA. Signals to be amplified are applied to the gate of the input FET. Additional stacked FETs are provided in series between the input FET and the output FET.
Field effect transistor circuits
A number of field effect transistor circuits include voltage controlled attenuators or voltage controlled processing circuits. Example circuits include modulators, lower distortion variable voltage controlled resistors, sine wave to triangle wave converters, and or servo controlled biasing circuits.
TRANSCONDUCTANCE AMPLIFIER BASED ON SELF-BIASED CASCODE STRUCTURE
Provided in the present invention is a transconductance amplifier based on a self-biased cascode structure. The transconductance amplifier includes a self-biased cascode input-stage structure constituted by PMOS (P-channel Metal Oxide Semiconductor) input transistors M1, M2, M3 and M4, a self-biased cascode first-stage load structure constituted by NMOS (N-channel Metal Oxide Semiconductor) transistors M5, M6, M7 and M8, a second-stage common-source amplifier structure constituted by an NMOS transistor M9 and a PMOS transistor M10, a bias circuit structure constituted by NMOS transistors M11 and M12 and a PMOS transistor M13, an amplifier compensation capacitor C.sub.c, an amplifier load capacitor C.sub.L, a reference current source Iref and a PMOS transistor MO that provides a constant current source function. Further provided in the present invention is a transconductance amplifier based on a self-biased cascode structure, which adopts an NMOS transistor as an input transistor. Both input transistors and load transistors of a first-stage amplifier of the present invention adopt self-biased cascode structures, such that the output impedance and the DC gain of the first-stage amplifier are increased. Substrate voltages of the MOS transistors of the first-stage amplifier are provided by an amplifier bias circuit. Owing to a connection mode of the compensation capacitor C.sub.c, a higher figure of merit is achieved.
Transconductance amplifier based on self-biased cascode structure
Provided in the present invention is a transconductance amplifier based on a self-biased cascode structure. The transconductance amplifier includes a self-biased cascode input-stage structure constituted by PMOS (P-channel Metal Oxide Semiconductor) input transistors M1, M2, M3 and M4, a self-biased cascode first-stage load structure constituted by NMOS (N-channel Metal Oxide Semiconductor) transistors M5, M6, M7 and M8, a second-stage common-source amplifier structure constituted by an NMOS transistor M9 and a PMOS transistor M10, a bias circuit structure constituted by NMOS transistors M11 and M12 and a PMOS transistor M13, an amplifier compensation capacitor C.sub.c, an amplifier load capacitor C.sub.L, a reference current source Iref and a PMOS transistor M0 that provides a constant current source function. Further provided in the present invention is a transconductance amplifier based on a self-biased cascode structure, which adopts an NMOS transistor as an input transistor. Both input transistors and load transistors of a first-stage amplifier of the present invention adopt self-biased cascode structures, such that the output impedance and the DC gain of the first-stage amplifier are increased. Substrate voltages of the MOS transistors of the first-stage amplifier are provided by an amplifier bias circuit. Owing to a connection mode of the compensation capacitor C.sub.c, a higher figure of merit is achieved.
Incore nuclear instrumentation system
In an encore nuclear instrumentation system which is equipped with a movable type neutron detector, an object of the invention is to control measurement errors due to the degradation of the system. The incore nuclear instrumentation system includes a neutron detector which is to be installed in a nuclear reactor stored in a containment vessel, and an instrumentation unit which has a current detector circuit and is to be installed on the outside of the containment vessel. An output signal of the neutron detector is inputted into the current detector circuit, and the instrumentation unit remembers a matrix which shows a relation among a reactor power of the nuclear reactor, a gain of the current detector circuit, and an output voltage Vn of the current detector circuit, and the calibration of the current detector circuit is performed with reference to the matrix.
Method and apparatus to optimize power clamping
A clamping circuit that may be used to provide efficient and effective voltage clamping in an RF front end. The clamping circuit comprises two series coupled signal path switches and a bypass switch coupled in parallel with the series coupled signal path switches. A diode is coupled from a point between the series coupled signal path switches to a reference potential. In addition, an output selection switch within an RF front end has integrated voltage clamping to more effectively clamp the output voltage from the RF front end. Additional output clamping circuits can be used at various places along a direct gain signal path, along an attenuated gain path and along a bypass path.
LNA with controlled phase bypass
In electronic circuits having various gain states, small gain phase shift differences required among various gain states may pose a challenging problem. The disclosed methods and devices provide solution to such challenge. Electronic circuits are described wherein a first path including an amplifier may be bypassed by a second path including only passive elements and for gain states smaller than 0 dB. In such electronic circuits, a phase shifter included in the second path can be adjusted to address the required phase shift among various gain states.
Closed-loop position control of MEMS micromirrors
Disclosed herein is a control system for a projection system, including a first subtractor receiving an input drive signal and a feedback signal and generating a first difference signal therefrom, the feedback signal being indicative of position of a quasi static micromirror of the projection system. A type-2 compensator receives the first difference signal and generates therefrom a first output signal. A derivative based controller receives the feedback signal and generates therefrom a second output signal. A second subtractor receives the first and second output signals and generates a second difference signal therefrom. The second difference signal serves to control a mirror driver of the projection system. A higher order resonance equalization circuit receives a pre-output signal from an analog front end of the projection system that is indicative of position of the quasi static micromirror, and generates the feedback signal therefrom.