Yousef Shakhsheer 3292011 1 VCOs Two criteria Generates a periodic output Needs selfsustaining oscillation mechanism 2 Important Metrics Frequency Power Tunability Range and linearity ID: 243855
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Slide1
Voltage Controlled Oscillators
Yousef Shakhsheer3/29/2011
1Slide2
VCOs
Two criteriaGenerates a periodic output.
Needs self-sustaining oscillation mechanism;
2Slide3
Important Metrics
FrequencyPowerTunability
(Range and linearity)
Jitter
Figure of Merit
3Slide4
Three Types of Oscillators
LC-TankRing oscillator
Crystal Oscillator
4Slide5
Important Issues
Inductors - inductance modeling and modeling of losses. TopologyVaractors
- Topology
Process Variation
Temperature
5Slide6
[1] A Sub-1–V 4-GHz CMOS VCO and a 12.5-GHz Oscillator for Low-Voltage and High-Frequency
Ahmed H.
Mostafa
,
Mourad
N. El-Gamal
,&
Ramez
A.
Rafla
6Slide7
7
Mostafa
et al, “A Sub-1–V 4-GHz CMOS VCO and a
12.5-GHz Oscillator for Low-Voltage and High-Frequency”Slide8
Topologies
4-,5- GHzVaractor
Tuning
10.5-,12.5- GHz
Back-gate Tuning
8
Mostafa
et al, “A Sub-1–V 4-GHz CMOS VCO and a
12.5-GHz Oscillator for Low-Voltage and High-Frequency”Slide9
[2] 1-V Ultra-Low-Power CMOS LC VCO for UHF
Quadrature Signal Generation
Zheng
Wang,
Huseyin
S. Savci,
Numan
S.
Dogan
9Slide10
Proposed Topology
10
Wang et al, “1-V Ultra-Low-Power CMOS LC VCO for UHF
Quadrature
Signal Generation”Slide11
11
Wang et al, “1-V Ultra-Low-Power CMOS LC VCO for
UHFQuadrature
Signal Generation”Slide12
[3] A Low-Complexity, Low-Phase-Noise, Low-Voltage Phase-Aligned Ring Oscillator in 90 nm Digital CMOS
Jonathan
Borremans
,
Julien
Ryckaert
, Claude
Desset
, Maarten
Kuijk
, Piet
Wambacq
, and Jan
Craninckx
,
12Slide13
Ring Oscillators
Problem:Inductors are hard to design
Jitter added over time in ring oscillator
Ring Oscillator:
Reset to reduce jitter, noise, power, etcVery simple circuitry
13
Borremans
et al, “A Low-Complexity, Low-Phase-Noise, Low-Voltage
Phase-Aligned Ring Oscillator in 90 nm Digital CMOS”Slide14
Results
14
Borremans
et al, “A Low-Complexity, Low-Phase-Noise, Low-Voltage
Phase-Aligned Ring Oscillator in 90 nm Digital CMOS”Slide15
[4] A Low-Power, Process-and-Temperature-Compensated Ring Oscillator With Addition-Based Current Source
Xuan
Zhang
, and Alyssa B.
Apsel
15Slide16
PVT Variation
16
Change from single transistor to current source for PVT
Zhang et al, “A Low-Power, Process-and-Temperature-
Compensated Ring Oscillator With Addition-Based Current Source”Slide17
17
Zhang et al, “A Low-Power, Process-and-Temperature-
Compensated Ring Oscillator With Addition-Based Current Source”Slide18
Variation
18
Zhang et al, “A Low-Power, Process-and-Temperature-
Compensated Ring Oscillator With Addition-Based Current Source”Slide19
[5] Low-Voltage, Low-Power and Low Phase Noise 2.4 GHz VCO for Medical Wireless Telemetry
Ahmed
Fakhr
, M. Jamal
Deen
and Hubert deBruin
19
Fakhr
et al, “Low-Voltage, Low-Power and Low Phase Noise 2.4 GHz VCO for Medical Wireless Telemetry”Slide20
Sub - VT
20
Fakhr
et al, “Low-Voltage, Low-Power and Low Phase
Noise 2.4 GHz VCO for Medical Wireless Telemetry”Slide21
Sub-VT
21
Fakhr
et al, “Low-Voltage, Low-Power and Low Phase
Noise 2.4 GHz VCO for Medical Wireless Telemetry”Slide22
Crystal
8.0 MHz - 50.0 MHz10 - 100 µW
http://www.abracon.com/Resonators/abm3b.pdf
22Slide23
Summing it all up
[1]
[2]
[3]
[4]
[5]
Technology
.25 um
.180 um
.090 um
.090 um
.180 um
Voltage
.85 V
1 V
.5 V
1 V
.4 V
Max Freq
4 GHz
1.6 GHz
400 MHz
1.8 GHz
2.4 GHz
Phase Noise
-84.7 @ 100 KHz
-121 @ 1 MHz
-119 @ 200 Hz
-109.76 @ 10 MHz
-123 @ 1 MHz
Power
4.08 mW
105 uW
1.8 mW
87 uW
41
uW
23Slide24
Other Good Resources
Razavi’s BookPerrott’s
slides
24