Advanced Materials Research Vol. 981

Abstract: Bandgap voltage reference, to provide a temperature and power supply insensitive output voltage, is a very important module in the analog integrated circuits and mixed-signal integrated circuits. In this paper, a high performance CMOS bandgap with low-power consumption has been designed. It can get the PTAT (Proportional to absolute temperature) current, and then get the reference voltage. Based on 0.35μm CMOS process, using HSPICE 2008 software for circuit simulation, the results showed that , when the temperature changes from -40 to 80 °C, the proposed circuit’s reference voltage achieve to 1.2V, temperature coefficient is 3.09ppm/°C. Adopt a series of measures, like ESD protection circuit, in layout design. The ultimately design through the DRC and LVS verification, and the final layout size is 700μm * 560μm.

Abstract: Area cost estimation model is important for accurate measurement of area on reconfigurable processor. However, in the process of CI (Custom Instruction), traditional model can’t accurately estimate area cost of CI candidates. In the paper, we propose a novel strategy of area cost estimation. According to island-style FPGA (Field Programmable Gate Array) structure, the strategy firstly enumerated all BCs (Basic Cells) from data-path of CI candidates. Then checked all the validity of BCs enumerated, and selected the unique BC set to overlap original data-paths. We lastly used the effective estimation model based on BC to accurately measure area cost of candidates. Experimental results show that novel strategy can accurately estimate area cost of CI candidates, which is very close to actual result from a HLS (High Level Synthesis) tool, and deviation is less than 6%.

Abstract: Thermoelectric Cooler (TEC), with typical advantages such as low acoustic noise, small volume, lightness, high performance and high reliability, is a compact device widely used in fields like military applications and cooling or heating small spaces. Circuit design of a real-time controlled, LED displayed and monitored cooling and heating system is presented in this paper. The system is consisted of STC89C52RC MCU, TEC1-12706, temperature monitoring chip DS18B20, LED temperature display unit etc. Five kinds of functions like heating or cooling automatically adjustable, temperature controlling, temperature real-time displaying and monitoring and limitation value settings are achieved. A high cooling/heating efficiency has been obtained. The test result shows that the temperature rise/decrease can be 6,83°C/2.18°C per minute in the early 5 operation process of this system.

Abstract: With the growth of the scale of SoC, function verification becomes more and more complicated. Traditional functional verification method is confronted with some challenges. This paper achieves coverage-driven, constrained-randomization and assertion verification methodology based on SystemVerilog and VMM, to build verification platform by taking example of EMI (external memory interface). As result of verification, we can monitor coverage, control the platform, optimize testbench and testcase, finish function coverage 100%. These applications can simplify complex function verification, improve the platform reuse, and meet the needs of chip verification.

Abstract: In this paper, noise analysis and characterization of a 5V CMOS interface circuit for the fluxgate is presented, which is based on second-harmonic detection of the output voltage. The circuit consists of oscillator, band pass filter, phase sensitive demodulation, low pass filter. The chip is fabricated in the 0.5μm two–metal and two-poly n-well CMOS process with an area of 4 mm2. Experimental results shows, the system exhibits a sensitivity of 16.5μV/nT for a magnetic field range of ±90μT in open-loop with 5kHz excitation frequency. Using 5V supply voltage, the power consumption of the system is measured to be 35 mW.

Abstract: An efficient three-stage amplifier with a new compensation method called single Miller capacitor feedforward compensation (SMFFC) which is suitable for large capacitive load applications are introduced in this paper. The overall layout area of the amplifier can be significantly reduced without influencing their stability by using a single Miller compensation capacitor in a three-stage amplifier. Pole-splitting and feedforward techniques are effectively combined in this compensation method to achieve a better performance.

Abstract: Sinusoidal signal generator is common electronic equipment. In this paper, the writer designed a kind of integrated CMOS sine signal generator, which generator uses wien bridge oscillation circuit.This generator circuit mainly constitutes by amplifier, leveled and low-pass filter circuit, which uses Cadence software to simulate and analysis its amplification circuit, in order to get a sine wave which has high performance accuracy and stability. Through simulating this generator, we can get a kind of sine wave which includes the frequency as the 1.109 kHz, the center potential as 2.5V, the amplitude as 2.58V, distortion is less than 2%, and this sine wave is more practical for the lower voltage supply system.  

Abstract: Σ-Δ modulator structure is increasingly becoming complex, it is very necessary to improve the design efficiency by the level of behavior model in the simulation. The paper discussed several important Σ-Δ modulators with ideal factors, and gives corresponding behavior model. Then, the paper shows a behavior level design with non-ideal factors. Under the condition that sample rate is 256 and input signal frequency is 250 KHz, the SNR can get 105 dB, the effective bit can get 16 bit. It can be used in audio and electronic equipment.

Abstract: In a vibratory microgyroscope, the nonlinear of the readout circuit is a critical part of the signal processing. This is because nonlinear can corrupt the resulting signals, including the angular velocity information. In this paper, issues related to nonliear are discussed. A detailed analysis of the effects caused by various nonidealities is provided. The nonlinear considered are as follows: the distance between the active comb and the fixed comb at the static modal and the equivalent capacitance at sensitive modal. In addition to the analysis of the nonlinear, which is necessary for a successful system-level design is provided.

Abstract: Erbium-doped fiber amplifiers is a signal light amplification of optical devices. This paper analyzes the impact of various fiber parameters on the noise figure, and characteristic of noise index has been simulated by means of OASIX software. The relationship between the pump power and noise figure, and fiber length and noise figure are obtained.