lecture1 overview 2014

8/13/2019 Lecture1 Overview 2014

1/18

Analog CMOS/VLSI Design, Spring 2014

Introduction

1

Introductory Remarks

Applications classes:Digital communication, wireless receivers, disk drive electronics,sensors, optical receivers, digital cameras, neural networks and,

believe it or not, microprocessors and memories todays

microprocessors and memories draw upon a great deal of

analog design expertise.

Why CMOS for digital?CMOS dissipates power only during switching and requires

only a few devices. It also scaled down more easily than the

other types of technologies. Also, lower fabrication costs.

Why CMOS for analog also?The principal force has been the scaling-down because it

has the dual benefit: improved speed of MOSFETs and

simultaneously reduction of chip size. The intrinsic speed

of MOS transistors has increased by more than 1000 in the

past 30 years. Multi-GHz analog circuits are now inproduction.


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Introduction

2

Some Example Applications

Digital Cameras (CMOS Cameras, or APS)

2m

poly

p-well

n +n +

p-substrate

p+p

p-well

n+ n+

Photo diode Reset TransistorTransfer Gate

0.5

10m

0.25m 0.12m

Circuit description

Note: most of the dimensions shown

above are now out of date

Vout

Reset(R)

VDD

Transfer

Gate (TG)

SF

Row Select

h

FD

Photodiode

(SF:Source

Follower


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Introduction

Some Example Applications

Digital Cameras (CMOS Cameras, or APS)

Question:

What is the most important device/component in a digital camera?

Answer:

The question is somewhat unfair, but even so one answer would be

the photodiode , which is reverse-biased.

Note also that if the camera has 10M pixels, then it would have 10M

photodiodes.


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Introduction

4

yellowrosespersonalservices.blogspot.com

Endoscopyshowing an abnormal growth

http://groups.csail.mit.edu/vision/medical-

vision/virtual-

endoscopy/Presentations/masterworks.ppt

http://www.paritymed

ical.com/display-

surgical-endoscopy-

barco-wide-screen.htm

Applications: consumer, business, industry, scientific, medicine


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Introduction

5

In the interest of simplicity, Metal-2 is not shown which provides the window/aperturefor the light to impinge on the photodiode.

Also, apMOS switch is shown which has the advantage of providing VD = VDD upon

reset but incurs extra area cost due to the nwell needed. So, an nMOS switch is more

popular even though it only provides a max VD = VDD - Vt upon reset.

Highly simplified figure showing the photodiode and the reset switch

p Substrate

Reset

Source

VDD

S

n Well

p substrate

D

p-transistorVD

VD


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Introduction

6

.

.

.

LNA

IF1

IF2

IFN

.

.

.

tCos c1

tSin c1

tCos c2

tSin c2

tCos cN

tSin cN

I

Q

Multiple RF bandsMultiple Standards Exist

Wideband LNA

Mixer (LNC)

Band-select

filter 1

Band-select

filter 2

Band-select

filter N

Multiband

antenna

(that resonates

at the desired

frequencies)

(possibly a

monopole

antenna)

Wireless Communications

Wideband

LNA


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Introduction

7

Simplified schematic of

a fully integrated LNA

Microphotograph of a CMOS LNA

Size: 0.93 mm 0.93 mm

Source unknown

CMOS LNA

Wireless Communications


8/18


Introduction

8

X-ray fan

X-ray tube

Read-out

Pre-amplification

A/D conversion

Projection acquisition

High voltage

generator

Gantry rotation

Tube control

Scan control or t

Physical data

correction

Image

reconstruction

Scan

protocol

Scan parameters: tube

current, rotation time,

collimated slice width,

table feed, etc.

Image reconstructionparameters: convolution

filter, reconstructed

slice width, image

orientation, matrix and

pixel size, etc.

Image

analysis

Slice

collimation

Multi-slice Spiral CT System

The X-ray tube and detector rows arc are mounted on a rotating gantry. The longitudinal coordinate of the data is

determined by the patient tables translation. The dashed lines indicate the user (technician) defined parameters.

x

y

z axis into the paper

Analog


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Introduction

9

PGS4 (fabricated in CMOS technology, 2010):

Overall layout of power transmission line sensing and analysis VLSI chip

(the sensing coil, on metal-2 (purple), and the driver coil on metal-1 (blue))

frontendb

Power Grid Sensor Chip


10/18


Introduction

10

Vin1

M2M1

M4M3

Vout

VDD

P

M5

Vin2

Vb3 M6

M7

Sensecoil

Drivercoil

orTXl

ine

Toanalog

MUX

Schematic of the frontend: differential amplifier

and a very-low output impedance source follower


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Introduction

11

frontend

(one of

threetypes

on the

chip)

This is onlya part of the

layout

on the chip.


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Introduction

12

As mentioned PGS4 chips were received in Dec. 2010 and were

tested in 2011.

PGS5, is the next advanced version; the chips were fabricated and

tested. It carries out Power Transmission Line fault distance

estimation, based on real (as opposed to complex valued)computations.

PGS6: carries out Power Transmission Line fault distance

estimation, based on complex valued computations. Theoryrequires such computations, although our simulations indicate that

real arithmetic may be adequate for some practical situations. Also

PGS6 incorporates non-contact voltage sensors.

Further on the horizon is our plan for a 3-D chip in the future.


13/18


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Introduction

14

Some application areas (a very incomplete list)

Biomedical systems

Sensors including bio-sensors

Optical systems, including digital cameras

Wireless communications

MEMS systems

Power systems, power grid electronics

Security systems

System on a chip


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Introduction

15

Even though on the previous few viewgraphs we have emphasized

power systems applications, the course will address principles ofdesign which target frequencies ranging from low to extremely-

extremely high frequencies.

We have already seen examples that range from

power frequencies to

(wireless) cell phone frequencies to

visible light frequencies toX-ray frequencies

This should become more clear on the next viewgraph.


16/18


Introduction

16

3k 30 300 3M 30 300 3G 30 300 3T 30 300 3P 30 300 3E 30 300

100Km 10Km 1Km 100m 10m 1m 10cm 1cm 1mm 100 10 1 100 10nm 1nm 100pm 10pm 1pmnm

Co-ax cable Optics

Hz

Electromagnetic Spectrum

1550 nm

kHz, MHz, GHz, TeraHz,

PetaHz (PHz),

ExaHz (EHz)

Hz

101010

333

201918

d i


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Introduction

17

What about rays. Yes, they are used in the so called Anger Camera forSPECT imaging. The rays emanate from the patientsbody after he/she has been administered trace amount of

appropriate radionuclide.

Scintillation crystals are used to detect and, in fact, multiply each rayphoton to visible band photons.

Each rayphoton can yield up to 40,000 visible band photons.

What then follows immediately, generally, is analog circuitry:

APS

PreamplifierSignal conditioning

A/D conversion

etc.

I d i


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Introduction

18

A general (and rather vague) question:

What are the frequencies that the human body deals with, or is

involved/concerned with?

Answer:

Sub-Hz to 1014 Hz and higher

A Few Examples (all data given below are somewhat simplistic):

(1) Human locomotion: Sub-Hz to a few Hz

(2) Heart rhythm (or cardiac rhythm): ~1Hz

(3) ECG: ~ 250 Hz (although some researchers have used

up to 1 kHz)

(4) Speech: up to about 15 kHz (the telephone system has

largely LP filtered it at ~4 kHz and used it successfully)

(5) Vision: > 1014 Hz

lecture1 overview 2014

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