A 4-ns BiCMOS translation-lookaside buffer

A 64-entry fully associative TLB (translation-lookaside buffer) with a pin-to-pin translation delay of 3.6 ns is described. This translation speed is achieved by using BiCMOS content-addressable memory (CAM) and SRAM arrays wherein small signal swings are maintained throughout the critical translation path. A BiCMOS CAM cell that uses a single bipolar translator to drive the match line is introduced. The TLB has been integrated as a stand-alone chip in an 0.8-μm BiCMOS technology. The circuit operates from a 5.2-V supply with ECL-compatible input and output levels. The power dissipation (excluding the power dissipated in the physical address output buffers) is less than 600 mW     

Design techniques for high-throughput BiCMOS self-timed SRAMs

Design techniques for a high-throughput BiCMOS self-timed SRAM are described. A new BiCMOS read circuit using a pipelined read architecture and a BiCMOS complementary clocked driver (BCCD) are proposed to reduce the operating cycle time. A 8192×9-b dual-port self-timed SRAM designed using the proposed techniques achieved a clock cycle time of 3.0 ns, that is, a 333-MHz operating frequency, by SPICE simulation on model parameters for 0.8-μm BiCMOS technology. A high-speed built-in self-test (BIST) circuit was studied and designed for the 3.0-ns cycle SRAM. It is confirmed that the BIST circuit allows the 3.0-ns cycle SRAM to test at its maximum operating frequency     

Power reduction techniques for a 1-Mb ECL-CMOS SRAM with an accesstime of 550 ps and an operating frequency of 900 MHz

This paper describes power reduction circuit techniques in an ultra-high-speed emitter-coupled logic (ECL)-CMOS SRAM. Introduction of a 0.25-μm MOS transistor allows a Y decoder and a bit-line driver to be composed of CMOS circuits, resulting in a power reduction of 34%. Moreover, a variable-impedance load has been proposed to reduce cycle time. A 1-Mb ECL-CMOS SRAM was developed by using these circuit techniques and 0.2-μm BiCMOS technology. The fabricated SRAM has an ultrafast access time of 550 ps and a high operating frequency of 900 MHz with a power dissipation of 43 W     

A 550-ps access 900-MHz 1-Mb ECL-CMOS SRAM

An ultrahigh-speed 1-Mb emitter-coupled logic (ECL)-CMOS SRAM with 550-ps clock-access time, 900-MHz operating frequency, and 12-μm² memory cells has been developed using 0.2-μm BiCMOS technology. Three key techniques for achieving the ultrahigh speed are a BiCMOS word decoder/driver with an nMOS level-shift circuit, a sense amplifier with a voltage-clamp circuit, and a BiCMOS write circuit with a variable-impedance bitline load. The proposed word decoder/driver and sense amplifier can reduce the delay times of the circuits to 54% and 53% of those of conventional circuits. The BiCMOS write circuit can reduce the power dissipation of the circuit by 74% without sacrificing writing speed. These techniques are especially useful for realizing ultrahigh-spaced high-density SRAMs, which will be used as cache and control memories in mainframe computers     

A 3.5-ns, 500-mW, 16-kbit BiCMOS ECL RAM

A 16-kbit BiCMOS ECL SRAM with a typical address access time of 3.5 ns and 500-mW power dissipation was developed. The RAM was fabricated using half-micrometer, triple-poly, and triple-metal BiCMOS technology. The fast access time with moderate power dissipation has been achieved using new circuit techniques: a grounded-gate, nonlatching-type level converter with a wired-OR predecoder and a direct column sensing scheme having a cascode differential amplifier. As a result of extensive use of high-speed bipolar ECL circuits with self-aligned bipolar transistors, the RAM attains high-speed performance without degrading the low-power BiCMOS RAM characteristics.<>     

An experimental 1-Mbit BiCMOS DRAM

Three developments are proposed for high-performance DRAMs: a bipolar complementary MOS (BiCMOS) DRAM device structure featuring high soft-error immunity due to a p/SUP +/ buried layer; a high-speed circuit configuration of eight NMOS subarrays combined with BiCMOS peripheral drivers and BiCMOS data output circuitry; and BiCMOS voltage and current limiters lowering power dissipation as well as peak current. A 1.3 /spl mu/m 1-Mb DRAM is designed and fabricated to verify the usefulness of these BiCMOS DRAM technologies. Features of this chip include a typical access time of 32 ns, a typical power dissipation of 450 mW at a 60-ns cycle time, and chip size of 5.0/spl times/14.9 mm/SUP 2/.     

用0.8μm工艺技术设计的65-kb BiCMOS SRAM

设计了一种65-kb BiCMOS静态随机存取存储器(SRAM)的存储单元及其外围电路,提出了采用先进的0.8mm BiCMOS工艺,制作所设计SRAM的一些技术要点。实验结果表明,所设计的BiCMOSSRAM,其电源电压可低于3V,它既保留了CMOS SRAM低功耗、高集成密度的长处,又获得了双极型(Bipolar)电路快速、大电流驱动能力的优点,因此,特别适用于高速缓冲静态存储系统和便携式数字电子设备中。     

An 8-ns 1-Mbit ECL BiCMOS SRAM with double-latch ECL-to-CMOS-level converters

The design and performance of a high-speed 1 M*1-bit SRAM with ECL I/O are described. The 6.5*16.5-mm/sup 2/ chip was fabricated with a 0.8- mu m BiCMOS process technology. A modified double-word-line (MDWL) structure and a bit-line peripheral circuitry with normally-on bit-line equalization circuit are used to achieve high-speed read operation. The read speed is further enhanced by a novel ECL-to-CMOS-level converter with a double-latch configuration. The converter dissipates no DC current and contributes to low power consumption together with an automatic power-saving function, utilizing the address transition detection (ATD) technique. The access time is typically 8 ns, and the active power is 500 mW at 50 MHz.<>     

A 10-bit video BiCMOS track-and-hold amplifier

A 1.2-μm VLSI BiCMOS technology has been used to implement a monolithic video track-and-hold amplifier that settles to an accuracy of 10 b in 15 ns. This level of performance is competitive with hybrid track-and-hold circuits and surpasses previously reported monolithic implementations by nearly two orders of magnitude. The amplifier's design is based on a closed-loop topology incorporating two BiCMOS folded-cascode gain stages, an NMOS sampling switch, and a BiCMOS switch driver with 1-ns transitions between ±4 V. The circuit operates from ±5-V power supplies and is capable of driving a 50-Ω load with ±1-V swings. For a fully differential implementation, the power dissipation is 1.2 W. The amplifier can be integrated either as a stand-alone track-and-hold circuit or as the front end of an analog-to-digital conversion system for video and high-speed instrumentation applications     

A 4-ns 4K×1-bit two-port BiCMOS SRAM

The authors introduce a two-port BiCMOS static random-access memory (SRAM) cell that combines ECL-level word-line voltage swings and emitter-follower bit-line coupling with a static CMOS latch for data storage. With this cell, referred to as a CMOS storage emitter access cell, it is possible to achieve access times comparable to those of high-speed bipolar SRAMs while preserving the high density and low power of CMOS memory arrays. The memory can be read and written simultaneously and is therefore well-suited to applications such as high-speed caches and video memories. A read access time of 3.8 ns at a power dissipation of 520 mW has been achieved in an experimental 4K×1-bit two-port memory integrated in a 1.5-μm 5-GHz BiCMOS technology. The access time in this prototype design is nearly temperature-insensitive, increasing to only 4 ns at a case temperature of 100°C     

TFT-LCD驱动控制电路芯片研究

研制成功一款彩屏手机用262144色132RGB×176-dot分辨率TFT-LCD单片集成驱动控制电路芯片,提出了基于低/中/高混合电压工艺、数模混合信号VLSI显示驱动芯片的设计及其验证方法,开发了SRAM访问时序冲突解决电路、二级输出驱动电路和动态负载补偿输出缓冲电路等新型电路结构,有效减小了电路的功耗和面积,抑制了回馈电压的影响,提高了液晶显示画面质量。采用0.25μm混合电压CMOS工艺实现的工程样片一次性流片成功,整个芯片的静态功耗约为5mW,输出灰度电压的安定时间小于30μs,芯片性能指标均达到设计要求。     

Trends in megabit DRAM circuit design

The state of the art in megabit dynamic random access memory (DRAM) circuit and chip design is reviewed in terms of essential design parameters such as signal-to-noise ratio, power dissipation, and speed. The memory cell signal charge has decreased gradually with an increase in memory cell size, despite the vertically structured cell designs. To offset this decrease, multidivided data-line structures, low-power design, and transposition of folded data lines are essential. To reduce power dissipation, an increase in the maximum refresh cycle and multidivided data lines combined with shared I/O in addition to a reduced operating voltage are efficient. A BiCMOS circuit provides a high-speed access time with low cost due to the high drivability of the driver and high sensitivity of the amplifier. It is predicted that the current DRAM technology might be diversified in the future so that a large-memory-capacity-oriented technology would coexist with a high-speed-oriented technology, posing power-supply standardization as a continuing serious concern     

Low-power CMOS/BiCMOS drivers and receivers for on-chipinterconnects

Novel low-voltage swing CMOS and BiCMOS driver/receiver circuits for low-power VLSI applications are proposed. Interconnect wire drivers with low output signal swing are employed. Special receivers provide single and double level conversion while minimizing the total driver/receiver transmission delay. These level converters have no DC power dissipation. At 3.3 V power supply voltage, the proposed circuits consume less power without delay penalty. The power saving is observed to be as high as 30%. At lower supplies further power and delay improvements are observed     

A new true-single-phase-clocking BiCMOS dynamic pipelined logicfamily for high-speed, low-voltage pipelined system applications

New true-single-phase-clocking (TSPC) BiCMOS/BiNMOS/BiPMOS dynamic logic circuits and BiCMOS/BiNMOS dynamic latch logic circuits for high-speed dynamic pipelined system applications are proposed and analyzed. In the proposed circuits, the bootstrapping technique is utilized to achieve fast near-full-swing operation. The circuit performance of the proposed new dynamic logic circuits and dynamic latch logic circuits in both domino and pipelined applications are simulated by using HSPICE with 1 μm BiCMOS technology. Simulation results have shown that the new dynamic logic circuits and dynamic latch logic circuits in both domino and pipelined applications have better speed performance than that of CMOS and other BiCMOS dynamic logic circuits as the supply voltage is scaled down to 2 V. The operating frequency and power dissipation/MHz of the pipelined system, which is constructed by the new clock-high-evaluate-BiCMOS dynamic latch logic circuit and clock-low-evaluate-BiCMOS (BiNMOS) dynamic latch logic circuit, and the logic units with two stacked MOS transistors, are about 2.36 (2.2) times and 1.15 (1.1) times those of the CMOS TSPC dynamic logic under 1.5-pF output loading at 2 V, respectively. Moreover, the chip area of these two BiCMOS pipelined systems is about 1.9 times and 1.7 times as compared with that of the CMOS TSPC pipelined system. A two-input dynamic AND gate fabricated with 1 μm BiCMOS technology verifies the speed advantage of the new BiNMOS dynamic logic circuit. Due to the excellent circuit performance in high-speed, low-voltage operation, the proposed new dynamic logic circuits and dynamic latch logic circuits are feasible for high-speed, low-voltage dynamic pipelined system applications     

A 1.5-ns 256-kb BiCMOS SRAM with 60-ps 11-K logic gates

A 1.5-ns address access time, 256-kb BiCMOS SRAM has been developed. To attain this ultra-high-speed access time, an emitter-coupled logic (ECL) word driver is used to access 6-T CMOS memory cells, eliminating the ECL-MOS level-shifter time delay. The RAM uses a low-power active pull down ECL decoder. The chip contains 11-K, 60-ps ECL circuit gates. It provides variable RAM configurations and general logic functions. RAM power consumption is 18 W; chip power consumption is 35 W. The chip is fabricated by using a 0.5-μm BiCMOS process. The memory cell size is 58 μm² and the chip size is 11×11 mm     

A 6-ns ECL 100 K I/O and 8-ns 3.3-V TTL I/O 4-Mb BiCMOS SRAM

The authors report a 4 M word×1 b/1 M word×4 b BiCMOS SRAM that can be metal mask programmed as either a 6-ns access time for an ECL 100 K I/O interface to an 8-ns access time for a 3.3-V TTL I/O interface. Die size is 18.87 mm×8.77 mm. Memory cell size is 5.8 μm×3.2 μm. In order to achieve such high-speed address access times the following technologies were developed: (1) a BiCMOS level converter that directly connects the ECL signal level to the CMOS level; (2) a high-speed BiCMOS circuit with low threshold voltage nMOSFETs; (3) a design method for determining the optimum number of decoder gate stages and the optimum size of gate transistors; (4) high-speed bipolar sensing circuits used at 3.3-V supply voltage; and (5) 0.55-μm BiCMOS process technology with a triple-well structure     

A 0.5-V 25-MHz 1-mW 256-kb MTCMOS/SOI SRAM for solar-power-operated portable personal digital equipment - sure write operation by using step-down negatively overdriven bitline scheme

Multithreshold-voltage CMOS (MTCMOS) technology has a great advantage in that it provides high-speed operation with low supply voltages of less than 1 V. A logic gate with low-V/sub th/ MOSFETs has a high operating speed, while a low-leakage power switch with a high-V/sub th/ MOSFET eliminates the off-leakage current during sleep time. By using MTCMOS circuits and silicon-on-insulator (SOI) devices, the authors have developed a 256-kb SRAM for solar-power-operated digital equipment. A double-threshold-voltage MOSFET (DTMOS) is adopted for the power switch to further reduce the off leakage. As regards the SRAM core design, we consider a hybrid configuration consisting of high-V/sub th/ and low-V/sub th/ MOSFETs (that is, multi-V/sub th/ CMOS). A new memory cell with a separate read-data path provides a larger readout current without degrading the static noise margin. A negatively overdriven bitline scheme guarantees sure write operation at ultralow supply voltages close to 0.5 V. In addition, a charge-transfer amplifier integrated with a selector and data latches for intrabus circuitry are installed to enhance the operating speed and/or reduce power dissipation. A 32K-word /spl times/ 8-bit SRAM chip, fabricated with the 0.35-/spl mu/m multi-V/sub th/ CMOS/SOI process, has successfully operated at 25 MHz under typical conditions with 0.5-V (SRAM core) and 1-V (I/O buffers) power supplies. The power dissipation during sleep time is less than 0.4 /spl mu/W and that for 25-MHz operation is 1 mW, excluding that of the I/O buffers.     

Circuit techniques for large CSEA SRAMs

The CMOS-storage emitter-access (CSEA) memory cell offers faster access than the MOS cells used in conventional BiCMOS SRAMs but using it in large memory arrays poses several problems. Novel BiCMOS circuit approaches to address the problems of decoding power, electronic noise, level translation, and write disturbance are described. Results on a 64-kb CSEA SRAM using these techniques are reported. The device, fabricated in an 0.8-μm BiCMOS technology, achieves read access and write pulse time of less than 4 ns while dissipating 1.7 W at a case temperature of 70°C     

全差分BiCMOS采样/保持电路仿真设计

在全差分折叠式共栅-共源运放的基础上,设计了一款BiCMOS采样/保持电路。该款电路采用输入自举开关来提高线性度,同时设计的高速、高精度运放,其建立时间tS只有1.37 ns,提升了电路的速度和精度。所设计的运放中的双通道共模反馈电路使共模电压稳定输出时间tW约达1.5 ns。采用SMIC公司的0.25μmBiCMOS工艺参数,在Cadence Spectre环境下进行了仿真实验,结果表明,当输入正弦电压频率fI为10 MHz、峰-峰值UP-P为1 V,且电源电压VDD为3 V、采样频率fS为250 MHz时,所设计的采样/保持电路的无杂散动态范围SFDR约为-61 dB,信噪比SNR约为62 dB,整个电路的功耗PD约为10.85 mW,适用于10位低压、高速A/D转换器的设计。     

BiCMOS nonthreshold logic for high-speed low-power applications

New high-speed low-power BiCMOS nonthreshold logic (BNTL) circuits are presented. These circuits offers a built-in CMOS and bipolar level conversion and are suitable for reduced power supply voltage. A 4-b carry lookahead generator (CLG) circuit is designed in BNTL, ECL, and CMOS using 0.8-μm BiCMOS technology. Circuit simulations show that this new logic provides speed comparable to or better than that provided by emitter-coupled logic (ECL) for lower power dissipation