一种12位25 MS/s采样保持电路设计

在流水线结构的A／D转换电路中,采样保持电路是整个电路的核心模块。同时采样保持电路通常是整个电路中功耗最大的模块,其性能直接决定了整个A／D转换器的性能。文章介绍了一种12位25MS／s采样保持电路。该采样保持电路采用SMIC0.25μm标准数字CMOS工艺进行设计。基于BSIM3V3Spice模型,采用Hspice对整个电路进行仿真。仿真的结果表明,电路在工作于25MS／s、输入信号频率为2．56MHz时,输出信号的SFDR为75．6dB,而整个电路的功耗仅为10．41mW。     

用于时间交织ADC的高精度开环跟踪保持电路设计

给出了一种适用于时间交织模数转换器（TI-ADC）的高速、高精度前端开环跟踪／保持（T＆rI）电路的设计方法。该方法针对开环电路本身的线性度比较差的特点,采用自举开关设计了一种高增益、高带宽的加强型源级跟随器,从而改善了开环电路的线性度,降低了功耗．并可在400MHz的采样频率和799．8047MHz的输入信号下,获得58．7dB的无杂散动态范围（SFDR）和9．5位的有效精度以及10．56mw的低功率消耗。     

一种用于流水线A/D转换器的低功耗采样/保持电路

文章介绍了一种适用于10位20MS／s流水线A／D转换器的采样／保持（S／H）电路。该电路为开关电容结构，以0．6μm DPDM CMOS工艺实现。采用差分信号输入结构，降低对共模噪声的敏感度，共模反馈电路的设计稳定了共模输出，以达到高精度。该S／H电路采用低功耗运算跨导放大器（OTA），在5V电源电压下，功耗仅为5mW。基于该S／H电路的流水线A／D转换器在20MHz采样率下，信噪比（SNR）为58dB，功耗为49mW。     

LTC2217：105Msps低噪声ADC

Linear推出低噪声、高性能16位、105Msps模数转换器（ADC）LTC2217,该器件具81．2dBFS信噪比（SNR）和100dBc．无寄生动态范围（SFDR）。超低抖动帮助在高输入频率时保持高SNR,在70MHz时可产生80．4dBFSSNR,同时高线性度采样／保持电路在70MHz时允许92dBFS的低失真。与需要两个电源的可替代ADC相比,单一3．3V电源需要较少的支持电路。     

一种12位高速低失真数字/模拟转换器的设计

介绍了一种12位高速、低失真数字/模拟转换器(DAC)的设计原理及其电路结构;着重阐述了去毛刺技术及其应用。采用2μm等平面隔离互补双极工艺模型参数进行了Cadence仿真。结果表明,该12位DAC在高达60MHz数据更新率下具有低于100pV·s的毛刺脉冲面积。     

基于BiCMOS技术设计的CS/VR电路

运用双极互补金属氧化物半导体（BiCMOS）的先进技术,设计了几个实用的电流源／基准电压源（CS／VR）电路,并籍助于通用电路模拟软件PSpice3.00,对它们进行了仿真研究。     

10bit 60Msps 15mW流水线ADC的设计

给出了一个SMIC0．13μmCMOS工艺的10bit／60MHz流水线ADC的设计方法。该电路去掉了采样保持电路,同时引入运放分享技术,从而大大降低了功耗。仿真结果显示。在60MHz时钟采样时,其ENOB为9．67bit,SFDR为75．2dB。     

基于0.35 μm GeSi-BiCMOS工艺的1 GSPS采样保持电路

介绍了一种基于0.35μmGeSi-BiCMOS工艺的1GSPS采样/保持电路。该电路采用全差分开环结构,使用局部反馈提高开环缓冲放大器的线性度;采用增益、失调数字校正电路补偿高频输入信号衰减和工艺匹配误差造成的失调。在1GS/s采样率、484.375MHz输入信号频率、3.3V电源电压下进行仿真。结果显示,电路的SFDR达到75.6dB,THD为-74.9dB,功耗87mW。将该采样/保持电路用于一个8位1GSPSA/D转换器。流片测试结果表明,在1GSPS采样率,240.123MHz和5.123MHz输入信号下,8位A/D转换器的SNR为41.39dB和43.19dB。     

高速12位D/A转换器

介绍了高速12位D/A转换器的电路设计,采用2μm等平面高速双极工艺,研制出数据更新率≥80MHz,线性误差≤3LSB,微分非线性≤3LSB的12位D/A转换器电路.     

一种低功耗高精度模数转换器的设计

本文描述一个基于0．25μm CMOS工艺的、低功耗的13b，15MS／s流水线ADC的设计。为了达到13b的转换精度，在电路设计中采用了电容误差平均技术和增益自举运算放大器；为了实现低功耗设计，在电路设计中综合采用了运算放大器共享、输入采样保持放大器消去、按比例缩小和动态比较器等技术。在考虑工艺实现中的非理想因素的条件下，对ADC电路进行晶体管级Monte-Carlo仿真，当ADC以15MHz的采样率对1．1MHz的正弦输入信号进行采样转换时，在其输出得到了80．8dBc的非杂散动态范围（SFDR），并且此时ADC模拟部分的功耗仅为10mW。结果表明：该ADC达到了13b15MS／S的设计性能，实现了低功耗的设计目标。     

高性能栅压自举开关的设计

对模数转换器中的传统开关电路的导通电阻进行了详细的理论分析,提出了一种互补型栅压自举开关电路.该电路结构相比于传统开关,通过少量的功耗代价换取了更优的频域性能,在不同工艺角下具有更好的鲁棒性,适用于先进工艺下的低电压工作环境.互补型栅压自举开关电路采用28 nm工艺设计,在1V的电源电压下,对800fF的负载电容进行速率为800 MS/s的采样,在低频输入下(181.25 MHz)实现的无杂散动态范围(SFDR)为89 dB,四倍奈奎斯特输入频率下(1 556 MHz)实现的SFDR为65 dB,开关电路面积为80 μm×20 μm.     

A synchronous phase-lock loop detector for integrated AM radio

A synchronous phase-lock loop AM detector has been realized on a single chip in a bipolar process with an f/SUB T/ of 400 MHz. The circuit accepts input signals at an IF frequency of 450-500 kHz with effective values between 20 and 100 mV. The phase-lock loop capture range is about 150 kHz. AM signals with over 80% modulation depth can be demodulated with less than 1% harmonic distortion in the audio output signal. The power dissipation of the chip is 120 mW at 8 V. The total chip size is 1900/spl times/1300 /spl mu/m/SUP 2/. Since the VCO and the 90/spl deg/ phase shift are completely realized on-chip, large signals at the IF frequency do not occur at the pins of the IC, and parasitic feedback of such signals to the IF amplifier input is minimized.     

一种用于视频信号处理的高速宽带运算放大器

基于高速亚微米互补双极工艺,设计了一种用于视频信号处理的高速宽带运算放大器。电路内部采用高速输入差分对、电流型放大单元、Rail-to-Rail输出单元等结构进行信号传输和放大。对开环增益提升、高速电压-电流信号转换、满摆幅输出设计以及频率稳定性补偿等关键技术进行分析,利用Spectre软件进行仿真。流片后的测试结果表明,在±5 V工作电压下,该放大器的－3 dB带宽≥200 MHz,失调电压≤5 mV,电源电流≤6 mA,满足高速通信、高速ADC前端信号采集、视频信号处理等各种场合的应用需求。     

一种12位80 MS/s CMOS流水线ADC设计

介绍了一种12 bit 80 MS/s流水线ADC的设计,用于基带信号处理,其中第一级采用了2.5 bit级电路,采样保持级采用了自举开关提高线性,后级电路采用了缩减技术,节省了芯片面积.采用了折叠增益自举运放,优化了运放的建立速度,节省了功耗.芯片采用HJTC0.18μm标准CMOS工艺,1.8 V电压供电,版图面积2.3 mm × 1.4 mm.版图后仿真表明,ADC在8 MHz正弦信号1 V峰值输入下,可以达到11.10 bit有效精度,SFDR达到80.16 dB,整个芯片的功耗为155 mW.     

An 8-b, 40 msamples/s switched-current-mode track-and-hold circuiton a BiCMOS sea-of-gates array

A fully differential track-and-hold circuit based on the switched-current processing has been integrated on a fully complementary 1.2 μm-6 GHz BiCMOS sea-of-gates array. It is based on a BiCMOS switched-current memory cell which uses MOS transistors to store the analog information and bipolar transistors to implement the switch. This improves the speed achievable and the distortion compared to a CMOS-only switched-current memory cell. A differential configuration is also presented which made it possible to improve performances such as the hold mode feedthrough (<-67 dB @ 10 MHz) or the pedestal error. The acquisition time for a full scale step is 22 ns, in order to reach the final value within 0.1%. It achieves 8-b precision at a sample-rate of 40 MHz under Nyquist condition, a full scale track-mode bandwidth of 150 MHz and a consumption of 80 mW for a surface of 0.44 mm²     

A 10-b 75-MSPS subranging A/D converter with integrated sample andhold

The design of a fully differential two-step analog-to-digital converter (ADC) is presented. A sample-and-hold (S/H) circuit based on a unity-gain feedback amplifier, flash ADCs driven by differential resistor ladders, and a differential digital-to-analog converter (DAC) combined with the subtractor are described. The chip has been fabricated in a standard high-speed bipolar process and, by extensively utilizing compensation techniques, achieves ±1 LSB integral nonlinearity and low harmonic distortion. A 75 Msample/s conversion rate not yet exceeded even by full-flash 10-b ADCs, has been achieved with a power consumption of 2 W. Due to the S/H circuit, the input bandwidth of 250 MHz; the effective resolution of 9 b at 5 MHz exhibits a gradual decrease over input frequency but still remains above 8 b up to 50 MHz     

A High Performance Track and Hold Circuit for High-Resolution High-Speed ADC

Design of a high performance track and hold (T/H) circuit for high-resolution high-speed analog-to-digital converter (ADC) is presented,which has been implemented in 0.18 μm CMOS process.An improved bootstrapped and bulk-switching technique is introduced to greatly minimize the nonlinearity of sampling network over a wide bandwidth,and the addition of a modified pre-charge circuit helps reducing the total power consumption.The experimental results show that the proposed T/H circuit achieves over 77 dB SFDR (spurious-free dynamic range) and 70 dB THD (total harmonic distortion) at 100 MHz sampling rate and maintains the performance with input frequency up to 305 MHz while consuming 47 mW power.     

A monolithic video A/D converter

The design and measured performance of a fully parallel monolithic 8-bit A/D converter is reported. The required comparators and combining logic were designed and fabricated with a standard high-performance triple-diffused technology. A bipolar comparator circuit giving good performance with high input impedance is described. Circuit operation is reported at sample rates up to 30 megasamples per second (MS/s), with analog input signal power at frequencies up to 6 MHz. Full 8-bit linearity was achieved. An SNR of 42-44 dB was observed at input signal frequencies up to 5.3 MHz.     

A channel unit signal controller for shared codec D-type channel banks

The channel unit signal controller is a 2.56 mm/spl times/2.56 mm beam-leaded silicon integrated circuit fabricated using the complementary bipolar integrated circuit (CBIC) technology with buried injector logic (BIL). The circuit handles the distribution of signals within a channel unit of a digital telecommunications system. Several diverse circuit functions are incorporated on this device including high-speed emitter-coupled logic, lower speed buried injector logic. JFET switches, high-speed pulse amplifiers to drive the JFETs, a voltage limiter, and a comparator circuit. The channel unit signal controller is described from system and circuit points of view and the CBIC/BIL process is described.     

A 10-bit 50-MS/s sample-and-hold circuit with low distortion sampling switches

A fully-differential switched-capacitor sample-and-hold (S/H) circuit used in a 10-bit 50-MS/s pipeline analog-to-digital converter (ADC) was designed and fabricated using a 0.35-μm CMOS process. Capacitor fliparound architecture was used in the S/H circuit to lower the power consumption. In addition, a gain-boosted operational transconductance amplifier (OTA) was designed with a DC gain of 94 dB and a unit gain bandwidth of 460 MHz at a phase margin of 63 degree, which matches the S/H circuit. A novel double-side bootstrapped switch was used, improving the precision of the whole circuit. The measured results have shown that the S/H circuit reaches a spurious free dynamic range (SFDR) of 67 dB and a signal-to-noise ratio (SNR) of 62.1 dB for a 2.5 MHz input signal with 50 MS/s sampling rate. The 0.12 mm2 S/H circuit operates from a 3.3 V supply and consumes 13.6 mW.