The Experts below are selected from a list of 60735 Experts worldwide ranked by ideXlab platform

Joy Zhang - One of the best experts on this subject based on the ideXlab platform.

  • A micropower chopper-stabilized operational amplifier using a SC notch filter with synchronous integration inside the continuous-time Signal Path
    IEEE Journal of Solid-State Circuits, 2006
    Co-Authors: Rod Burt, Joy Zhang
    Abstract:

    A micropower chopper stabilized opamp is presented. The new topology incorporates a switched capacitor filter with synchronous integration inside the continuous time Signal Path virtually eliminating chopping noise. A three-stage amplifier with multiPath nested Miller compensation is modified to incorporate chopping of the input stage, sinc filtering to notch any chopping ripple, and a compensation scheme to maintain an undistorted high-speed Signal Path. Characteristics of the amplifier presented include rail to rail input and output operating on supplies of 1.8 to 5.5 V over -40degC to 125degC. Quiescent supply current is 17 muA, input offset is 3 muV, input offset drift is 0.02 muV/degC, GBW is 350 kHz, and the chopping frequency is 125 kHz. Die area is 0.7 mm2 using a precision analog mixed-Signal CMOS process combining low-noise 0.6-mum analog transistors with 0.3-mum digital CMOS capability

Rod Burt - One of the best experts on this subject based on the ideXlab platform.

  • A micropower chopper-stabilized operational amplifier using a SC notch filter with synchronous integration inside the continuous-time Signal Path
    IEEE Journal of Solid-State Circuits, 2006
    Co-Authors: Rod Burt, Joy Zhang
    Abstract:

    A micropower chopper stabilized opamp is presented. The new topology incorporates a switched capacitor filter with synchronous integration inside the continuous time Signal Path virtually eliminating chopping noise. A three-stage amplifier with multiPath nested Miller compensation is modified to incorporate chopping of the input stage, sinc filtering to notch any chopping ripple, and a compensation scheme to maintain an undistorted high-speed Signal Path. Characteristics of the amplifier presented include rail to rail input and output operating on supplies of 1.8 to 5.5 V over -40degC to 125degC. Quiescent supply current is 17 muA, input offset is 3 muV, input offset drift is 0.02 muV/degC, GBW is 350 kHz, and the chopping frequency is 125 kHz. Die area is 0.7 mm2 using a precision analog mixed-Signal CMOS process combining low-noise 0.6-mum analog transistors with 0.3-mum digital CMOS capability

Gabor C Temes - One of the best experts on this subject based on the ideXlab platform.

  • switched capacitor track and hold amplifiers with low sensitivity to op amp imperfections
    IEEE Transactions on Circuits and Systems, 2007
    Co-Authors: Hirokazu Yoshizawa, Gabor C Temes
    Abstract:

    This paper describes high-precision switched-capacitor (SC) track-and-hold amplifier (THA) stages. They use a novel continuous-time correlated double sampling (CDS) scheme to desensitize the operation to amplifier imperfections. Unlike earlier predictive-CDS amplifiers, the circuits do not need a sampled-and-held input Signal for their operation. During the tracking period, an auxiliary continuous-time Signal Path is established, which predicts the output voltage during the holding period. This allows accurate operation even for low amplifier gains and large offsets over a wide input frequency range. Extensive simulations were performed to compare the performance of the proposed THAs with earlier circuits utilizing CDS. The results verify that their operation is far more robust than that of any previously described SC amplifiers

  • switched capacitor track and hold amplifier with low sensitivity to op amp imperfections
    Analog Integrated Circuits and Signal Processing, 2006
    Co-Authors: Hirokazu Yoshizawa, Gabor C Temes
    Abstract:

    This paper describes a high-precision switched-capacitor (SC) track-and-hold amplifier (THA) stage. It uses a novel continuous-time correlated double sampling (CDS) scheme to desensitize the operation to amplifier imperfections. Unlike earlier predictive-CDS THAs, the circuit does not need a sample-and-held input Signal for its operation. During the tracking period, an auxiliary continuous-time Signal Path is established, which predicts the output voltage during the holding period. This allows accurate operation even for low amplifier gains and large offsets over a wide input frequency range. Extensive simulations were performed to compare the performance of the proposed THA with earlier circuits utilizing CDS. The results verify that its operation is far more robust than that of any previously described THA.

John A C Bingham - One of the best experts on this subject based on the ideXlab platform.

  • a data driven multitone echo canceller
    IEEE Transactions on Communications, 1994
    Co-Authors: John A C Bingham
    Abstract:

    A data-driven echo canceller for full-duplex data transmission with multitone modulation is presented. This multitone echo canceller (MTEC) is not impaired by eigenvalue-spread problems that are inherent in Signal-driven echo cancellers-it has numerical performance and cancellation range that equals, and in most cases exceeds, that of data-driven echo cancellers used in data transmission with baseband or quadrature amplitude modulation. The method makes use of frequency-domain updating, but time-domain implementation of the canceller. It introduces no delay into the received Signal Path and presents no special difficulties for interframe interpolation between near-end echo, far-end echo, or far-end data Signal. The authors also investigate the fast initialization and the special case of far-end frequency offset in the echo Signal. >

  • a data driven multitone echo canceller
    Global Communications Conference, 1991
    Co-Authors: John A C Bingham
    Abstract:

    A data-driven echo canceller for full-duplex data transmission with multitone modulation is presented. This echo canceller is shown not to be impaired by the eigenvalue-spread problems that are inherent in Signal-driven echo cancellers, and to have numerical performance and cancellation range that equals, and in most cases exceeds, that of data-driven echo cancellers used in data transmission with baseband or quadrature amplitude modulation. The method makes use of frequency-domain updating, but with time-domain implementation of the canceller. It introduces no delay into the received Signal Path. >

Yencheng Kuan - One of the best experts on this subject based on the ideXlab platform.

  • A K/Ka/V Triband Single-Signal-Path Receiver With Variable-Gain Low-Noise Amplifier and Constant-Gain Phase Shifter in 28-nm CMOS
    IEEE Transactions on Microwave Theory and Techniques, 2021
    Co-Authors: Liang Chia-jen, Chingwen Chiang, Jia Zhou, Rulin Huang, Kueiann Wen, Mauchung Frank Chang, Yan Zhang, Yencheng Kuan
    Abstract:

    This article presents a single-Signal-Path tri (K/Ka/V)-band receiver (RX) featuring area/cost-effective support for various millimeter-wave phased-array applications. A triple-coupling transformer (TCT) at the common-gate input stage of the RX low-noise amplifier (LNA) is proposed for triband impedance matching and gₘ-boosting. By augmenting each low-parasitic pMOS switched inductor load with a pMOS variable resistor in parallel, the variable-gain functionality is merged into this LNA to cover a wide input-Signal range in a low-overhead manner. An active single-balanced mixer (SBM) for radio frequency (RF)-intermediate frequency (IF) downconversion is adopted to eliminate a wideband balun. Poor RF-IF and LO-IF isolations and low IIP₂ normally inherited in an SBM are avoided by setting the IF particularly. The wideband response of an on-chip local-oscillator (LO) buffer is realized through input resistor coupling and output inductor peaking. Furthermore, a constant-gain phase shifter (CGPS) at IF is proposed to benefit the orthogonal gain-and-phase control preferred by beam steering. This CGPS uses an amplitude-only feedback loop to retain the gain without baseband equalization. Fabricated in a 28-nm bulk CMOS technology, this RX exhibits variable power gains of 12.5-33.2 dB (at 24 GHz), 13.4-34.6 dB (at 33 GHz), and 3.1-32 dB (at 50 GHz) with respective minimum noise figures of 4.78, 5.12, and 6.15 dB. The respective RX 3-dB bandwidths are 20-27, 30-34.6, and 42-55.5 GHz. The measured CGPS gain variation at IF (2-4 GHz) is within 0.94 dB. This RX consumes 131 mW and occupies 1.22 mm² with pads in a silicon area.

  • a tri k ka v band monolithic cmos low noise amplifier with shared Signal Path and variable gains
    International Microwave Symposium, 2020
    Co-Authors: Chiajen Liang, Chingwen Chiang, Jia Zhou, Rulin Huang, Kueiann Wen, Mauchung Frank Chang, Yencheng Kuan
    Abstract:

    This paper presents a single-Signal-Path tri-band (K/Ka/V) variable-gain low noise amplifier (LNA) fabricated in 28-nm bulk CMOS technology. This LNA uses a common-gate input stage with a triple-coupling transformer (TCT) to achieve better impedance matching across three desired bands than those of prior arts and to enable the necessary gm-boosting to suppress undesired noise. Each LNA stage (except the final one) is loaded with a PMOS switched inductor carefully designed to trade off parasitic capacitances/resistances between off/on states. PMOS devices are also used in parallel with switched inductors as variable resistors to realize the variable gain functionality. Accordingly, the load quality factors can be changed to make the LNA power gain adjustable. This LNA consists of six stages and offers variable power gains from -5.5 to 29.9 dB (24 GHz), -5.5 to 32.4 dB (33 GHz), and -11.5 to 22.2 dB (50 GHz) with respective minimum noise figures of 5.63 dB, 4.55 dB, and 5.96 dB. This LNA consumes 25.6 mW from a 1-V supply and occupies 0.22 mm2 without pads in silicon area.