Voltage Controlled Oscillators - PowerPoint Presentation

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

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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

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PVT Variation

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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

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Zhang et al, “A Low-Power, Process-and-Temperature-

Compensated Ring Oscillator With Addition-Based Current Source”Slide18

Variation

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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

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Fakhr

et al, “Low-Voltage, Low-Power and Low Phase Noise 2.4 GHz VCO for Medical Wireless Telemetry”Slide20

Sub - VT

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Fakhr

et al, “Low-Voltage, Low-Power and Low Phase

Noise 2.4 GHz VCO for Medical Wireless Telemetry”Slide21

Sub-VT

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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

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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

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Other Good Resources

Razavi’s BookPerrott’s

slides

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