共查询到20条相似文献,搜索用时 125 毫秒
1.
Venkatesh Srinivasan Syed K. Islam Benjamin J. Blalock 《Analog Integrated Circuits and Signal Processing》2003,34(3):259-263
The variation of phase noise across the frequency of operation of a CMOS ring oscillator is described analytically. The delay element of the ring oscillator considered comprises of a source-coupled differential pair with an active load element. In this circuit topology where the frequency of oscillation is varied by changing the resistance of the load, theory derived in this work predicts that phase noise will remain constant if constant output swing is maintained. Such an oscillator is designed in a 0.5 m CMOS process and the simulation results verify the theoretical analysis. Consequently, an oscillator design methodology is provided that dramatically reduces the phase noise optimization problem to just one frequency within the oscillator's output frequency range. 相似文献
2.
Leung K.N. Lo C.H. Mok P.K.T. Mai Y.Y. Leung W.Y. Chan M.J. 《Electronics letters》2007,43(15):786-787
The design of a temperature-compensated CMOS ring oscillator is introduced. The concept is to make use of a linear, positively or negatively temperature-sloped supply voltage to power-up the ring oscillator. Experimental results show that the oscillation frequency remains fairly constant using the proposed scheme. 相似文献
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本文提出了一种基于65nm CMOS标准工艺、采用粗调和细调相结合的低噪声环形压控振荡器。论文分析了环形振荡器中的直接频率调制机理,并采用开关电容阵列来减小环形压控振荡器的增益从而抑制直接频率调制效应。开关电容采用电容密度较高的二维叠层MOM电容使该压控振荡器与标准的CMOS工艺兼容。所设计压控振荡器的频率范围为480MHz~1100MHz,调谐范围为78%,测试得到输出频率为495MHz时的相位噪声为-120dBc/Hz@1MHz。该压控振荡器在1.2V的偏压下的功耗为3.84mW,相应的优值(FOM)为-169dBc/Hz。 相似文献
4.
一款用于LED驱动芯片的CMOS振荡器 总被引:1,自引:0,他引:1
研究一款适用于LED驱动芯片的CMOS振荡器电路.其工作原理是在环路振荡器中加入恒定电流源,以恒定电流对电容充电、MOS管对电容快速放电以产生锯齿波再经锁存器产生周期脉冲信号.与传统的环路振荡器相比,此电路的优点是振荡频率精确、波形稳定,振荡频率在一定的电源电压范围内对电源电压变化不敏感.此振荡器电路已经成功应用于一款LED驱动芯片中. 相似文献
5.
A complementary metal oxide semiconductor (CMOS) voltage controlled ring oscillator for ultra high frequency (UHF) radio frequency identification (RFID) readers has been realized and characterized. Fabricated in charter 0.35 μm CMOS process, the total chip size is 0.47×0.67 mm2. While excluding the pads, the core area is only 0.15×0.2 mm2. At a supply voltage of 3.3 V, the measured power consumption is 66 mW including the output buffer for 50 Ω testing load. This proposed voltage-controlled ring oscillator exhibits a low phase noise of - 116 dBc/Hz at 10 MHz offset from the center frequency of 922.5 MHz and a lower tuning gain through the use of coarse/fine frequency control. 相似文献
6.
给出了一个采用0.6um CMOS工艺设计的改进结构环形振荡器,电路由RC充放电回路、施密特单元以及反相延时单元组成,结构简单,工作频率受集成电路工艺参数影响小。该电路带有使能控制端,并且通过调节少量的外部元件可以改变电路的振荡频率,适用作各类中/低频数字集成电路中的时钟产生电路。分析了改进结构环形振荡器的工作原理,给出了Hspice软件环境下电路仿真方法。电路流片封装后的实际测试结果表明,用该结构的环形振荡器作为时钟产生电路,工作稳定,满足了系统工作要求。 相似文献
7.
A Low-Noise Multi-GHz CMOS Multiloop Ring Oscillator With Coarse and Fine Frequency Tuning 总被引:1,自引:0,他引:1
《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2009,17(4):571-577
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RF Oscillator Based on a Passive RC Bandpass Filter 总被引:1,自引:0,他引:1
《Solid-State Circuits, IEEE Journal of》2009,44(11):3092-3101
10.
Sheng-Lyang Jang Chang-Hao Yang Miin-Horng Juang 《International Journal of Electronics》2013,100(7):691-697
A 6-phase divide-by-3 CMOS injection locked frequency dividers (ILFDs) have been proposed and implemented in a 0.35 μm CMOS process. The ILFD circuits are realised with a 3-stage double cross-coupled CMOS ring oscillator. The self-oscillating voltage controlled oscillator (VCO) is injection-locked by 3th-harmonic input to obtain the division factor of 3. Measurement results show that as the supply voltage varies from 1.2 to 3.5 V, the free-running frequency is from 0.136 to 0.7 GHz. At the incident power of ?5 dBm, the locking range in the divide-by-3 mode is from the incident frequency 0.38–2.31 GHz. 相似文献
11.
Jang S.-L. Chuang Y.-H. Lee S.-H. Chao J.-J. 《Microwave and Wireless Components Letters, IEEE》2007,17(3):217-219
This letter describes circuit techniques for obtaining divide-by-four (divide4) frequency dividers (FDs) from CMOS ring-oscillator based injection locked frequency dividers (ILFDs). The circuit is made of a two-stage differential CMOS ring oscillator and is based on MOS switches directly coupled to the differential outputs of the ring oscillator. At the supply voltage of 1.8V and at the incident power of 0dBm, for a dual-band ILFD, the divide4 ILFD can provide a locking range of 6.3% from 5.39 to 6.12GHz at low band and 5.9% from 8.84 to 9.38GHz at high band when the dc bias of MOS switches Vinj changes from 0.7 to 1.1V 相似文献
12.
Yun-Hsueh Chuang Sheng-Lyang Jang Shao-Hwa Lee 《Microwave and Wireless Components Letters, IEEE》2007,17(6):460-462
This letter proposes a new wide band CMOS injection locked frequency divider (ILFD). The circuit is made of a two-stage differential CMOS ring oscillator and is based on MOS switches directly coupled to the differential outputs of the ring oscillator. A tuning circuit composed of inductors in series with a metal oxide semiconductor field effect transistor is used to extend the locking range. The divide-by-two ILFD can provide wide locking range and the measured results show that at the supply voltage of 1.8 V, the free-running frequency of the ILFD is operating from 0.92 to 3.6 GHz while the Vtune is tuned from 0 to 1.8 V. At the incident power of 0 dBm, this ILFD has a wide locking range from 1.15 to 7.4 GHz 相似文献
13.
By utilizing the first order behavior of the device,an equation for the frequency of operation of the submicron CMOS ring oscillator is presented.A 5-stage ring oscillator is utilized as the initial design,with different Beta ratios,for the computation of the operating frequency.Later on,the circuit simulation is performed from 5-stage till 23-stage,with the range of oscillating frequency being 3.0817 and 0.6705 GHz respectively.It is noted that the output frequency is inversely proportional to the square of the device length,and when the value of Beta ratio is used as 2.3,a difference of 3.64% is observed on an average,in between the computed and the simulated values of frequency.As an outcome,the derived equation can be utilized,with the inclusion of an empirical constant in general,for arriving at the ring oscillator circuit's output frequency. 相似文献
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Co-integration of GaAs MESFET and Si CMOS circuits is demonstrated using GaAs-on-Si epitaxial growth on prefabricated Si wafers. This is thought to be the first report of circuit-level integration of the two types of devices in a coplanar structure. A 2-μm gate Si CMOS ring oscillator has shown a minimum delay of 570 ps/gate, whereas on the same wafer a 1-μm gate GaAs MESFET buffered-FET-logic (BFL) ring oscillator has a minimum delay of only 70 ps/gate. A composite ring oscillator consisting of Si CMOS invertors and GaAs MESFET invertors connected in a ring has been successfully fabricated 相似文献
16.
Jamel Nebhen Stéphane Meillère Mohamed Masmoudi Jean-Luc Seguin Hervé Barthelemy Khalifa Aguir 《Journal of Signal Processing Systems》2014,75(1):47-54
This paper presents a CMOS voltage controlled ring oscillator (VCO) with temperature compensation circuit suitable for low-cost and low-power MEMS gas sensor. This compensated ring oscillator is dedicated to Chopper Stabilized CMOS Amplifier (CHS-A). To operate at low frequency, a control voltage generated by a CMOS bandgap reference (BGR) is described and the measurement results of the fabricated chips are presented. The output voltage of the reference is set by resistive subdivision. In order to achieve small area and low power consumption, n-well resistors are used. This design features a reference voltage of 1 V. The chip is fabricated in AMS 0.35 μm CMOS process with an area of 0.032 mm2. Operating at 1.25 V, the output frequency is within 200?±?l0 kHz over the temperature range of ?25 °C to 80 °C with power consumption of 810 μW. 相似文献
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《Microwave and Wireless Components Letters, IEEE》2009,19(5):314-316
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This paper presents the design of three- and nine-stage voltage-controlled ring oscillators that were fabricated in TSMC 0.18-/spl mu/m CMOS technology with oscillation frequencies up to 5.9 GHz. The circuits use a multiple-pass loop architecture and delay stages with cross-coupled FETs to aid in the switching speed and to improve the noise parameters. Measurements show that the oscillators have linear frequency-voltage characteristics over a wide tuning range, with the three- and nine-stage rings resulting in frequency ranges of 5.16-5.93 GHz and 1.1-1.86 GHz, respectively. The measured phase noise of the nine-stage ring oscillator was -105.5 dBc/Hz at a 1-MHz offset from a 1.81-GHz center frequency, whereas the value for the three-stage ring oscillator was simulated to be -99.5 dBc/Hz at a 1-MHz offset from a 5.79-GHz center frequency. 相似文献
20.
CMOS inductorless voltage controlled oscillator (VCO) design is discussed with the emphasis on low-noise, low-power, gigahertz-range circuits suitable for portable wireless equipment. The paper considers three VCO structures-one simple ring oscillator and two differential circuits. The design methodology followed optimization for high-speed and low-power consumption. The proposed linearized MOSFET model allows the accurate prediction of the operating frequency while the phase noise evaluation technique makes it possible to determine, through simulation, the relative phase-noise performance of different oscillator architectures. The measurement results of three VCO's implemented in 1.2-μm CMOS technology confirm with the simulation predictions. The prototype VCO's exhibits 926-MHz operation with -83 dBc/Hz phase noise (@ 100 kHz carrier offset) and 5 mW (5 V) power consumption 相似文献