A new constant-<Emphasis Type="Italic">Q</Emphasis> CMOS active inductor with applications to low-noise oscillators

This paper investigates the dependence of the quality factor of CMOS active inductors on the signal swing of the inductors and its impact on the phase noise of LC-tank oscillators employing the active inductors. A new CMOS active inductor with a nearly constant quality factor is proposed. Two 4-GHz LC oscillators with and without constant-Q active inductors have been implemented in UMC-0.13 μm 1.2 V CMOS technology and analyzed using SpectreRF from Cadence with BSIM3V3 device models. Simulation results demonstrate the phase noise of the oscillator with the constant-Q active inductor is −118dBc/Hz at 1 MHz frequency offset.     

A single capacitor loop filter phase-locked loop with frequency voltage converter

A novel phase-locked loop that has a loop filter consisting of only one capacitor is designed with a frequency voltage converter (FVC). Simulation and measurement results show that the proposed phase-locked loop (PLL) works stably demonstrating that the FVC works effectively as a resistor. Measurement results of the proposed PLL fabricated in a one-poly six-metal 0.18 μm CMOS process show that the phase noise is ?109 dBc/Hz at 10 MHz offset from 752.7 MHz output frequency.     

Current-Mode Phase-Locked Loops— A New Architecture

This brief introduces current-mode phase-locked loops (PLLs). The proposed current-mode PLLs differ from conventional voltage-mode PLLs by replacing their RC loop filter with a RL loop filter, eliminating the need for large on-chip capacitors. The large inductance of the current-mode loop filter is obtained from CMOS active inductors, taking the advantage of their large and tunable inductance and small silicon area. Both types I and II current-mode PLLs are introduced. Implemented in TSMC 0.18-mum CMOS technology, the simulation results of a 3-GHz current-mode PLL demonstrate that the PLL has the lock time 50 ns, silicon area 2800 mum², dc power consumption 12.2 mW, and phase noise of -84.5 dBc at 1-MHz frequency offset and the maximum -74 dBc reference spurs     

A 1.6-GHz CMOS PLL with on-chip loop filter

A 1.6-GHz phase locked loop (PLL) has been fabricated in a 0.6-μm CMOS technology. The PLL consists of an LC-tank circuit, divider, phase detector with charge pump, and an on-chip passive loop filter. When the oscillator is open loop, it exhibits -115 dBc/Hz phase noise at a 600-kHz offset from the carrier. The PLL occupies an active area of 1.6 mm² and dissipates 90 mW from a single 3-V supply     

Design of active inductor-based current-controlled oscillators using gm/Id methodology

This paper presents a novel design procedure based on gm/Id methodology to achieve a trade-off between tuning range, phase noise and output swing of active-inductor-based current-controlled oscillators (CCOs). It is shown that equations for the phase noise and corner frequency of the selected CCO configuration are related to the gm/Id parameters. In accordance with the above relations, the designed CCO is simulated using 0.18 µm TSMC CMOS technology parameters. The simulation exhibits a tuning range of 432 MHz to 3.54 GHz, a phase noise in the range of −84 dBc/Hz to −104.6 dBc/Hz at 1 MHz offset from carrier and a figure of merit of 178.4 dB in 1.453 GHz.     

基于电感电容振荡器的电荷泵锁相环的设计

设计并实现了一种采用电感电容振荡器的电荷泵锁相环,分析了锁相环中鉴频/鉴相器(PFD)、电荷泵(CP)、环路滤波器(LP)、电感电容压控振荡器(VCO)的电路结构和设计考虑。锁相环芯片采用0.13μm MS&RF CMOS工艺制造。测试结果表明,锁相环锁定的频率为5.6～6.9 GHz。在6.25 GHz时,参考杂散为-51.57 dBc;1 MHz频偏处相位噪声为-98.35 dBc/Hz;10 MHz频偏处相位噪声为-120.3 dBc/Hz;在1.2 V/3.3 V电源电压下,锁相环的功耗为51.6 mW。芯片总面积为1.334 mm2。     

Current-Mode Phase-Locked Loops With CMOS Active Transformers

This paper introduces active transformer current- mode phase-locked loops (PLLs). The proposed PLLs replaces the RC loop filter of voltage-mode PLLs with an active transformer loop filter to take the advantage of their large inductance and small silicon area. A current-controlled LC oscillator with active inductors is employed to further reduce silicon area. The sensitivity of the cutoff frequency of active transformer loop filter to supply voltage fluctuation and process variation is analyzed. A 3-GHz PLL has been implemented in TSMC 0.18- $mu$m 6-metal 1.8-V CMOS technology and analyzed using SpectreRF with BSIM3v3 device models and Verilog-AMS from Cadence Design Systems. The lock time of the PLL is 60 ns. The power consumption and phase noise of the PLL are 16 mW and ${-}$100 dBc/Hz at 1-MHz frequency offset, respectively. The layout area of the PLL is 2800 $mu hbox{m}^2$.      

A low jitter, low spur multiphase phase-locked loop for an IR-UWB receiver

A low jitter,low spur multiphase phase-locked loop(PLL) for an impulse radio ultra-wideband(IR-UWB) receiver is presented.The PLL is based on a ring oscillator in order to simultaneously meet the jitter requirement, low power consumption and multiphase clock output.In this design,a noise and matching improved voltage-controlled oscillator(VCO) is devised to enhance the timing accuracy and phase noise performance of multiphase clocks.By good matching achieved in the charge pump and careful choice of the l...     

A constant loop bandwidth in delta sigma fractional-N PLL frequency synthesizer with phase noise cancellation

This work presents the design of a new and unique design technique of constant loop bandwidth and phase-noise cancellation in a wideband ΔΣ fractional-N PLL frequency synthesizer. Phase noise performance of the proposed ΔΣ fractional-N PLL frequency synthesizer has been verified using CppSim simulator with the help of transistor level simulation results in Cadence SpecctreRF. Transient response of the proposed ΔΣ fractional-N PLL has been verified in transistor level simulation using Cadence SpectreRF in 0.13 μm standard CMOS process. The proposed phase-noise cancellation and constant loop bandwidth in wideband ΔΣ fractional-N PLL reduces the out of band phase noise by 18 dBc/Hz at 2 MHz offset frequency for a closed loop bandwidth of 1 MHz, when I_CP,max is equal to 2.6 mA. PLL locking time has been reduced with phase-noise cancellation and a constant loop bandwidth calibration circuits using the proposed CP unit current cell for the mismatch compensated PFD/DAC in wideband ΔΣ fractional-N PLL frequency synthesizer. Optimum phase noise performance can be achieved with the help of proposed design technique. Proposed ΔΣ fractional-N PLL frequency synthesizer is locked within 14.0 μs with an automatic frequency control circuit of the LC VCO and a constant loop bandwidth calibration circuit through the use of proposed CP unit current cell for the mismatch compensated PFD/DAC for the phase-noise cancellation in worst case condition of K_VFC = 10 and K_LBC = 150. Our new design technique can be extensively integrated for wideband fractional-N PLL for new type of wireless communication paradigm using the thinnest channel subharmonic transistor and low power devices, and it has the potential to open a new era of fractional-N PLLs for wideband application.     

Wide tuning-range CMOS VCO based on a tunable active inductor

In this paper, a wide tuning-range CMOS voltage-controlled oscillator (VCO) with high output power using an active inductor circuit is presented. In this VCO design, the coarse frequency is achieved by tuning the integrated active inductor. The circuit has been simulated using a 0.18-µm CMOS fabrication process and presents output frequency range from 100 MHz to 2.5 GHz, resulting in a tuning range of 96%. The phase noise is –85 dBc/Hz at a 1 MHz frequency offset. The output power is from –3 dBm at 2.55 GHz to +14 dBm at 167 MHz. The active inductor power dissipation is 6.5 mW and the total power consumption is 16.27 mW when operating on a 1.8 V supply voltage. By comparing this active inductor architecture VCO with general VCO topology, the result shows that this topology, which employs the proposed active inductor, produces a better performance.     

A 4224 MHz low jitter phase-locked loop in 0.13-μm CMOS technology

A 4224 MHz phase-locked loop (PLL) is implemented in 0.13 μm CMOS technology. A dynamic phase frequency detector is employed to shorten the delay reset time so as to minimize the noise introduced by the charge pump. Dynamic mismatch of charge pump is considered. By balancing the switch signals of the charge pump, a good dynamic matching characteristic is achieved. A high-speed digital frequency divider with balanced input load is also designed to improve in-band phase noise performance. The 4224 MHz PLL achieves phase noises of-94 dBc/Hz and -114.4 dBc/Hz at frequency offsets of 10 kHz and 1 MHz, respectively. The integrated RMS jitter of the PLL is 0.57 ps (100 Hz to 100 MHz) and the PLL has a reference spur of-63 dB with the second order passive low pass filter.     

A 1-V 24-GHz 17.5-mW phase-locked loop in a 0.18-/spl mu/m CMOS process

A 1-V 24-GHz 17.5-mW fully integrated phase-locked loop employing a transformer-feedback voltage-controlled oscillator and a stacked divide-by-2 frequency divider for low voltage and low power is presented. Implemented in a 0.18-/spl mu/m CMOS process and operated at 24 GHz with a 1-V supply, the PLL measures in-band phase noise of -106.3 dBc at a frequency offset of 100 kHz and out-of-band phase noise of -119.1 dBc/Hz at a frequency offset of 10 MHz. The PLL dissipates 17.5 mW and occupies a core area of 0.55 mm/sup 2/.     

A low phase noise PLL using Vackar VCO and a wide-locking range tunable divider for V-band signal generation in 65-nm CMOS

This paper presents a low phase noise integer-N phase-locked loop (PLL) for V-band signal generation. To enhance the frequency stability, we use a new class of Vackar voltage-controlled oscillator (VCO) in the PLL. The Vackar VCO achieves a low phase noise performance by effectively suppressing the AM-PM conversion. To properly align the locking range with the output of the VCO, a divider with wide locking range is realized by the current-mode logic (CML) D-flip-flops with tunable load. For spur reduction, an enhanced charge-pump structure is used to reject transient current glitches. With good static and dynamic current matching achieved in the charge pump, the reference spur is suppressed down to ?50 dBc. The designed PLL is implemented in a 65 nm RFCMOS process, and the measurement demonstrates a low phase noise signal up to 17 GHz. The in-band phase noise (at 1 MHz offset) and out-band phase noise (at 50 MHz offset) are ?103.6 and ?126.8 dBc/Hz, respectively. The PLL consumes 50.7 mW and occupies a chip area of 0.9 mm².     

LC-VCOs using spiral inductors with single- and dual-layer patterned floating shields: a comparative study

This letter studies and compares class-B VCOs using spiral inductors with the proposed dual-layer patterned floating shield (DL-PFS) and conventional single-layer patterned floating shield (SL-PFS). The proposed DL-PFS technique utilizes two lowest metal layers to effectively reduce the capacitive induced current to the substrate in an on-chip spiral inductor, thereby boosts its Q-factor by 40% when compared with the conventional SL-PFS approach. We fabricated, as a proof of concept, the class-B LC-VCOs using the DL-PFS and SL-PFS in 0.13 µm CMOS. Operating at 10 GHz, the VCO with the DL-PFS inductor measures a 3.6 dB phase noise (PN) improvement at the same power consumption of 2.12 mW. Specifically, the VCO with DL-PFS inductor is tunable from 9.3-to-10.1 GHz and measured PN at 10 GHz is ?132.5 dBc/Hz at 10 MHz offset while consuming 2.12 mW at the lowest 0.6 V supply. The achieved figure-of-merit (187.4 dBc/Hz@1 MHz offset) compares favorably with the recent state-of-the-art.     

Floating active inductor based Class-C VCO with 8 digitally tuned sub-bands

A fully integrated floating active inductor based voltage-controlled oscillator (VCO) is presented. The active inductor employs voltage differencing transconductance amplifier (VDTA) as a building block. The designed VCO achieves frequency tuning by varying the bias current through the VDTA and utilizes a Class-C topology for improving the phase noise performance. The inductor-less VCO is designed and implemented in a 45-nm CMOS process and its performance is estimated using Virtuoso ADE of Cadence. Operating at a supply voltage of ±1 V, the proposed VCO consumes 0.44–1.1 mW corresponding to the oscillation frequency of 1.1–1.8 GHz thereby exhibiting a tuning range of 48.27%. The phase noise of the VCO lies in the range of −94.12 to −98.37 dBc/Hz at 1 MHz offset resulting in a FOM of −172.14 to −176.69 dBc/Hz.     

A CMOS frequency synthesizer with an injection-locked frequencydivider for a 5-GHz wireless LAN receiver

A fully integrated 5-GHz phase-locked loop (PLL) based frequency synthesizer is designed in a 0.24 μm CMOS technology. The power consumption of the synthesizer is significantly reduced by using a tracking injection-locked frequency divider (ILFD) as the first frequency divider in the PLL feedback loop. On-chip spiral inductors with patterned ground shields are also optimized to reduce the VCO and ILFD power consumption and to maximize the locking range of the ILFD. The synthesizer consumes 25 mW of power of which only 3.8 mW is consumed by the VCO and the ILFD combined. The PLL has a bandwidth of 280 kHz and a phase noise of -101 dBc/Hz at 1 MHz offset frequency. The spurious sidebands at the center of adjacent channels are less than -54 dBc     

Design challenges of a 65 nm CMOS stacked folded differential PA structure for mobile communications

In this paper, a novel phase-locked loop (PLL) architecture with multiple charge pumps, which is used to design a fast-locking PLL and a low-phase-noise PLL, is proposed. The effective capacitance and resistance of the loop filter in terms of voltage is scaled up/down according to the locking status by controlling the magnitude and direction of the charge pump current. Two PLLs, one with a fast-locking characteristic and the other with a low-phase-noise characteristic, are designed and fabricated in a 0.35-μm CMOS process based on the proposed architecture. The fast-locking PLL has a locking time of less than 6 μs and a phase noise of −90.45 dBc/Hz at 1 MHz offset. The low-phase-noise PLL has a locking time of 25 μs, a phase noise of −105.37 dBc/Hz at 1 MHz offset, and a reference spur of −50 dBc. Both PLLs have an 851.2 MHz output frequency.     

A multiple-pass ring oscillator based dual-loop phase-locked loop

A dual-loop phase-locked loop (PLL) for wideband operation is proposed. The dual-loop architecture combines a coarse-tuning loop with a fine-tuning one, enabling a wide tuning range and low voltage-controlled oscillator (VCO) gain without poisoning phase noise and reference spur suppression performance. An analysis of the phase noise and reference spur of the dual-loop PLL is emphasized. A novel multiple-pass ring VCO is designed for the dual-loop application. It utilizes both voltage-control and current-control simultaneously in the delay cell. The PLL is fabricated in Jazz 0.18-μm RF CMOS technology. The measured tuning range is from 4.2 to 5.9 GHz. It achieves a low phase noise of-99 dBc/Hz @ 1 MHz offset from a 5.5 GHz carrier.     

A Low‐Spur CMOS PLL Using Differential Compensation Scheme

This paper proposes LC voltage‐controlled oscillator (VCO) phase‐locked loop (PLL) and ring‐VCO PLL topologies with low‐phase noise. Differential control loops are used for the PLL locking through a symmetrical transformer‐resonator or bilaterally controlled varactor pair. A differential compensation mechanism suppresses out‐band spurious tones. The prototypes of the proposed PLL are implemented in a CMOS 65‐nm or 45‐nm process. The measured results of the LC‐VCO PLL show operation frequencies of 3.5 GHz to 5.6 GHz, a phase noise of –118 dBc/Hz at a 1 MHz offset, and a spur rejection of 66 dBc, while dissipating 3.2 mA at a 1 V supply. The ring‐VCO PLL shows a phase noise of –95 dBc/Hz at a 1 MHz offset, operation frequencies of 1.2 GHz to 2.04 GHz, and a spur rejection of 59 dBc, while dissipating 5.4 mA at a 1.1 V supply.     

U波段小数分频锁相环型频率综合器

使用0.18μm1.8VCMOS工艺实现了U波段小数分频锁相环型频率综合器,除压控振荡器(VCO)的调谐电感和锁相环路的无源滤波器外,其他模块都集成在片内。锁相环采用了带有开关电容阵列(SCA)的LC-VCO实现了宽频范围,使用3阶MASHΔ-Σ调制技术进行噪声整形降低了带内噪声。测试结果表明,频率综合器频率范围达到650～920MHz;波段内偏离中心频率100kHz处的相位噪声为-82dBc/Hz,1MHz处的相位噪声为-121dBc/Hz;最小频率分辨率为15Hz;在1.8V工作电压下,功耗为22mW。