一种微功耗轨到轨输出AB类运算放大器设计

在分析研究AB类运算放大器的输入和输出级构成原理基础上,提出一种与信号处理模块的输出端匹配并具有一定负载能力的缓冲器的设计。缓冲器采用了AB类运放结构,其输入级采用折叠式共射共基结构,输出级分别采用PNP管和NMOS管作为上拉管和下拉管,结合电路结构的改进使之具有轨到轨(rail-to-rail)的输出特性和很低的静态电流。设计的电路具有开环增益大、静态功耗小、带宽较高等特点。此运放已在1.5μmBCD工艺下实现。测试结果表明,静态电流仅为8.5μA,闭环带宽达200kHz,开环增益为100dB。     

低功耗单双电源供电的轨对轨仪表放大器AD627

AD627是美国ADI公司出品的仪表放大器，它采用单双电源供电，具有轨对轨输出，并可用一个外部寄存器设定增益。可用于低功耗医用检测设备、热电耦放大器和便携式电池供电等仪器中。文章介绍了AD627的主要技术性能、工作原理、应用设计以及应用电路。     

低功耗升压型PFM DC-DC转换器

设计了一种低功耗升压型PFMDC-DC转换器。提出了一种新颖的驱动电路结构,该驱动电路的预充电功能大大地缩短了功率开关管的开启响应时间,减小了"硬开关"损耗,提高了系统的转换效率,并且详细地阐述了系统工作原理以及PFM信号的产生过程。测试结果表明,系统正常工作时的静态电流为50!A,停机模式的静态电流小于1!A,Vin低至0.9V时系统仍能正常工作,限流值为350mA,输出电压高达34V,最高转换效率为85%。     

A Micropower Chopper-Stabilized Operational Amplifier Using a SC Notch Filter With Synchronous Integration Inside the Continuous-Time Signal Path

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     

SW4391微功耗反相型开关电源

详细介绍了ＳＷ４３９１微功耗反相型开关电源的工作原理，线路设计，版图设计及研制结果，说明了其使用注意事项，并讨论了几种典型应用。     

Micropower switched-capacitor oscillator

A CMOS sinusoidal integrated oscillator based on a switched-capacitor third-order phase-shift network is described. Frequency is proportional to that of a clock, but may be controlled by a voltage. Accuracy is a few percent for a power consumption below 0.1 /spl mu/W in the audio range.     

A Micropower Adaptive Linear Transform Vector Quantiser

Micropower signal classification and compression are becoming important requirements for implantable cardioverter defibrillators although they are currently limited by power and computational constraints. This paper describes an integrated circuit that facilitates Intracardiac Electrogram (ICEG) classification and compression of 30 dimensional analogue vectors while consuming a maximum of 2.5 W power for a heart rate of 60 beats per minute (1 vector per second) from a 3.3 V supply. This represents a significant advance on previous work which achieved ultra low power supervised morphology classification [6] since the templated matching scheme used in this chip enables unsupervised blind classification of abnormal rhythms and the computational support for low bit rate data compression. The adaptive template matching scheme used is tolerant to amplitude variations, and inter- and intra-sample time shifts. Micropower performance is achieved using CMOS analogue circuits biased in weak inversion in order to minimise energy per computation. Results from the fabricated chip demonstrate the impact of the amplitude and shift tolerance on ICEG data and performance for blind classification of an abnormal rhythm in five heart patients. For four out of the five patients, no false negative classifications and a worst case of 11% false positive classifications were made.     

微功耗A32xx系列霍尔开关

A32xx系列霍尔开关型传感器是美国AllegroMicrosystems公司生产的微功耗霍尔开关芯片 ,文中介绍了这种霍尔开关器件的特性原理和封装形式 ,分析了A32xx器件的构成原理和工作特性 ,给出了A32xx系列器件在低功耗应用时的限制条件。     

Micropower log-domain active inductor

An alternative implementation for emulating an active inductor is proposed. Based on a classical gyrator active inductor architecture, the new active inductor is implemented by using a log-domain current integrator instead of a voltage integrator. Inductance and Q-factor can be tuned independently Simulation results confirming the idea are shown. The proposed circuit is a micropower active inductor operating in the weak inversion region of the MOSFETs     

A High Temperature Micropower Capacitive Pressure Sensor Interface Circuit

A pressure sensor interface circuit featuring micropower consumptionis presented. The sensitivity to leakage currents has been reduced, allowingoperation at high temperature. Special attention has been paid to minimisealiasing in the sampled interface. An optimal combination of contradictoryrequirements on power consumption, temperature range and sampling speed wasobtained by a very careful system design and optimisation. The circuitconverts a sensor capacitance variation of ±5pF into an 11 bit outputword at a 2Hz rate. This resolution is guaranteed in the –40°C to100°C temperature range. It may slowly decay above 100°C but ensuresat least 5 bit at 130°C. The power consumption at room temperature issmaller than 2µA from a 2.4V to 4V battery.     

A 1 V Micropower FGMOS Class AB Log-Domain Filter

A novel first-order CMOS log-domain filter is presented. The internal voltage swing compression due to its instantaneous voltage companding nature, together with the use of Floating-Gate MOS transistors and its class AB differential topology, allows operation with a single 1 V supply while maintaining at the same time a large input range. Moreover, operation in weak inversion leads to very low power consumption. The filter can be tuned in more than one decade through its bias currents. Simulation and measurement results of an experimental prototype fabricated in a 0.8 μm CMOS technology demonstrate on silicon the feasibility of the proposed technique, which can be readily extended to higher-order filters.     

Micropower switched capacitor biquadratic cell

The implementation of the double correlated sampling noise reduction technique in conventional strays-insensitive switched capacitor biquad building blocks is described. The function is performed by an offset cancellation circuit which is incorporated into the structure without the use of any additional capacitor, only minor modifications in the switching topology, and one supplementary clock phase. Consequently, a significant reduction of the low-frequency (1/f) noise is made possible and the usual differential amplifiers may be replaced by simple inverting amplifiers operated in class AB, featuring high-speed, low-quiescent power dissipation and low noise. An experimental micropower SC biquadratic filter section designed for `leapfrog' or `follow-the-leader feedback' structures has been developed using high gain (>80 dB) CMOS push/pull inverting amplifiers together with a three-phase clocking sequence. The integrated circuit, implemented in a low-voltage Si-gate CMOS process, achieves excellent accuracy and less than 5 /spl mu/W power dissipation with a 32 kHz sampling rate and /spl plusmn/1.5 V supplies; dynamic range is 66 dB.     

A Micropower Interface ASIC for a Capacitive 3-Axis Micro-Accelerometer

In this paper, a micropower interface IC for a capacitive 3-axis micro-accelerometer implemented in a 0.13- BiCMOS process is presented. The sensor interface consists of a front-end that converts the acceleration signal to voltage, two algorithmic ADCs, two frequency references, and a voltage, current, and temperature reference circuit. Die area and power dissipation are reduced by using time-multiplexed sampling and varying duty cycles down to 0.3%. The chip with a 0.51 active area draws 62 from a 1.8 V supply while sampling temperature at 100 Hz, and four proof masses, each at 1.04 kHz. With a 4-g capacitive 3-axis accelerometer, the measured noise floors in the x-, y-, and z-directions are 482 , 639 , and 662 , respectively.     

Micropower gradient flow acoustic localizer

A micropower mixed-signal system-on-chip for three-dimensional localization of a broad-band acoustic source is presented. Direction cosines of the source are obtained by relating spatial and temporal differentials in the acoustic traveling wave field acquired across four coplanar microphones at subwavelength spacing. Correlated double sampling and least-squares adaptive cancellation of common-mode leakthrough in the switched-capacitor analog differentials boost localization accuracy at very low aperture. A second stage of mixed-signal least-squares adaptation directly produces digital estimates of the direction cosines. The 3mm /spl times/ 3mm chip in 0.5-/spl mu/m CMOS technology quantizes signal delays with 250-ns resolution at 16-kHz sampling rate, and dissipates 54 /spl mu/W power from a 3-V supply. Field tests of the processor with acoustic enclosure demonstrated its utility and endurance in tracking ground and airborne vehicles. Applications include acoustic surveillance, interactive multimedia, and intelligent hearing aids.     

Solar Thermoelectric Generator for Micropower Applications

Solar thermoelectric generators (STG) using cheap parabolic concentrators with high-ZT modules can be a cost-effective alternative to solar photovoltaics for micropower generation. A thermodynamic analysis is presented for predicting the thermal-to-electrical conversion efficiency for the generator. With solar concentration of 66× suns, a system efficiency of 3% was measured for a commercial Bi₂Te₃ module with output power of 1.8 W. Using novel thermoelectric materials such as n-type ErAs:(InGaAs)_1−x (InAlAs) _x and p-type (AgSbTe) _x (PbSnTe)_1−x , a conversion efficiency of 5.6% can be achieved for a STG at 120× suns.     

Micropower arcsine circuit for tilt processing

An increasing number of medical devices, including implantable prosthetics and body-worn instrumentation, are incorporating sense systems within and around the body. One such sensor is the inclinometer (or tilt sensor), which senses its orientation with respect to gravity. Tilt sensors have typically been implemented using hybrid structures incorporating a stationary reference and movable mass. Traditionally these have been realised using electrolytic fluid-filled cavities. More recently a breed of modern silicon-based inclinometers have emerged implemented in various MEMS technologies [1?3]. It has also been shown how to derive inclination using an unmodified accelerometer [4].     

Micropower Electronic Switches for Implanted Instrumentation

Low-power miniature switching circuits for controlling the power supply to an implanted electronic circuit are described. These circuits can be used as power supply switches for conserving battery power on implanted systems. Monostable and bistable switches that can be triggered either by radio-frequency energy or light are presented. Circuits, having standby currents as low as 25 nA and operated at voltages of 1.35 V, are described. A hybrid microelectronics realization of a radio-frequency triggered bistable switch is described. Radio-frequency triggering by induction can be carried out over distances ranging from 2 to 10 cm, depending on the circuit used. Light triggering using either electronic photoflash lamps or low-power incandescent lights can be achieved over distances as great as 250 cm.     

Low Voltage Micropower Log-Domain Filters

A design technique for low-voltage, micropower continuous-time filters implementing CMOS devices operating in weak inversion is presented. The basic building block is the CMOS log-domain integrator. The effects of the MOS device nonidealities on the integrator are investigated and verified by HSPICE simulations. A 5th-order Chebyshev lowpass ladder filter was designed and simulated. The filter operates with low supply voltage of 1.5 V to achieve a cutoff frequency tunable range of 100 Hz–100 kHz, and it has a power dissipation of 254 nW/pole at the cutoff frequency of 100 kHz. The filter was laid out using the 0.35-m mixed-mode polycide CMOS technology and occupies a die area of 0.04 mm² without the i/o pads     

Micropower front-end interface for differential-capacitive sensor systems

A front-end circuit for interfacing to differential capacitive sensors, including certain microelectromechanical systems, is presented. The system combines a self-resetting, biphasic integrator with a difference timer, producing a word parallel output representing the differential capacitance. The measurable capacitance range is tunable by means of an input current bias and system clock frequency. For an input bias of 10 nA and system clock of 128 KHz, the measurable capacitance range is + /^-5pF (to 8 bit resolution) consuming below 26 muW total system power.     

微功率升压开关稳压器及其应用

介绍微功率升压开关稳压器电路MIC2142的特性及其应用电路。