A wideband low‐spur 0.18‐µm CMOS phase‐locked loop with bandwidth calibration

SummaryThis paper presents more compatible three‐stage inverter‐based ring voltage controlled oscillators (VCOs) by modifying the current‐starved delay cell to oscillate with high tuning range. Unlike some ring structures in which extra transistors are used as current boosting to enhance the frequency tuning range, no extra elements are used in the proposed three‐stage VCOs for increasing the tuning range. Besides, a new method is introduced to couple two proposed ring VCOs for designing a six‐phase ring VCO. The coupling method can be generalized to some other ring VCOs to generate multiphase signals. The proposed circuits have wide frequency tuning ranges and show good noise performances. The proposed six‐phase VCO can oscillate from 1.62 GHz to 3.45 GHz, which illustrates 72.2% tuning range. The phase noise of the proposed VCO is −97.5 dBc/Hz at 1 MHz offset frequency. The circuit figure of merit is −181.5 dBc/Hz. The post‐layout simulation results of the proposed six‐phase VCO are provided based on the TSMC 0.18 μm CMOS process.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Novel six‐phase ring voltage controlled oscillator with wide frequency tuning range

Hemmati,

Dehghani

2024

“…Here, the first stage of the frequency divider acts as a pre-scaler to support the subsequent low-frequency divider stages. 5,6 A transformer-based high-order resonator was reported to enhance the locking range of the millimeter-wave injection-locked frequency dividers in Zhang et al 5 An injection locking based, speed and power-optimized current mode logic (CML) frequency divider was proposed in Zhou et al, 7 where an active inductor tank is used to achieve high performance. The specifications of frequency dividers are demanding, particularly above 10-GHz applications, because of their operation at the maximum frequency of synthesizers.…”

Section: Introductionmentioning

confidence: 99%

Power and area‐efficient static current mode logic frequency divider in 180‐nm complementary metal‐oxide‐semiconductor technology

Maity

Jana

Som

et al. 2021

This paper presents power and area optimized, high-speed metal-oxidesemiconductor (MOS) current mode logic (MCML)-based frequency dividers. Each differential pair in the divider is sized separately to minimize the overall power consumption. The divide-by-2 frequency divider has been realized in a 180-nm complementary MOS (CMOS) process technology, and postlayout simulation results show that the proposed frequency divider can work up to an operating frequency of 18.8 GHz in the worst-case process corner with a maximum power dissipation of 1.715 mW under 1.8-V supply. It gives a bandwidth of 19.9 GHz which ranges from 1 to 20.9 GHz. The divider occupies a 0.106 Â 0.09 mm 2 area. The performance corresponds to the figure of merit (FoM) of 43.61 dB. The same optimized latches and two EX-OR gates are used to design a divide-by-5 frequency divider that is also realized in 180-nm CMOS process technology. The postlayout simulation results show that the proposed divide-by-5 frequency divider can faithfully work up to an operating frequency of 12.12 GHz in worst-case process corner with an excellent power head performance. The maximum power dissipation of the core circuit is 1.39 mW under 1.8-V supply. It occupies a 0.166 Â 0.116 mm 2 area. The performance corresponds to the FoM of 26.56 dB which compares favorably with the state of the art.

“…The PLL is a closed‐loop feedback system that estimates the frequency and phase angle of its input signals when it is in lock. On the other hand, oscillator is an amplifier with the positive feedback loop in which the frequency is the function of the voltage …”

Section: Introductionmentioning

confidence: 99%

“…On the other hand, oscillator is an amplifier with the positive feedback loop in which the frequency is the function of the voltage. [2][3][4][5][6][7] VCOs can be classified in two types: the LC-VCO and ring-VCO. 1 Each type has different frequency tuning methods.…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of differential ring voltage controlled oscillator for wide tuning range and low power applications

Аскари

Saneei

2018

Summary Voltage‐controlled oscillator (VCO) is the most basic component required for all wireless and communication systems. In this article, a four‐stage differential ring VCO with two control voltages for wide tuning range is proposed. This VCO uses the dual‐delay loop technique for high operation frequency. Also, a low‐VT NMOS transistor is used in series with pull down network of the proposed VCO delay cell to achieve low frequencies. Prelayout simulation of the proposed VCO is performed in 65‐nm TSMC CMOS technology in Cadence software under 1.2‐V supply voltage. The tuning range of the proposed VCO varies from 1 MHz to 13.8 GHz and has been improved by 19.77% compared to other works. The power consumption of this low power VCO is between 29.3 μW to 1.715 mW. The phase noise of the proposed circuit is −82.3 dBc/Hz at 1 MHz offset frequency and −106.9 dBc/Hz at 10 MHz offset frequency from 5.161 GHz center frequency, while its area is 102.457 μm2. This design demonstrates other benefits in low power consumption and area compared with other ring oscillators.