ee 221.3 t1 - 2016 - college of engineering 1_signals.pdf · – text book: "microelectronic...

EE 221.3 T1 - 2016• Anh Dinh: 3B14 ENGR, Tel: 966-5344, email: [email protected]

• Class Website: http://www.engr.usask.ca/classes/EE/221/ + Blackboard

• Lecture (M,W,F) + Labs (Th,F):– Text book: "Microelectronic Circuits,” 7th Ed., Sedra/Smith

(Ch.1,2,3,4,5,6,7).

– Equipment: Analog Discovery PortableAnalog Circuit Design Kit Available at SESS office (1C12 ENGR)

– Waveforms Software: http://www.digilentinc.com/Products/Detail.cfm?Prod=ANALOG-DISCOVERY

• Mark distribution:– Final Exam : 50%– Midterm : 20% – Assignments : 10% – Labs: 20% – Note that, to pass the course, you must pass at least one of the final or midterm

examination.

mailto:[email protected]

http://www.engr.usask.ca/classes/EE/221/

Points to remember1. A circuit must be completed in a loop

2. Laws in electricity: Kirchhoff’s (voltage and current) and Ohm’s laws

1. Voltage is the potential difference in charge between 2 points in the circuit

2. Current in a circuit is inversely proportional to the resistance (impedance) in the circuit

3. Thevenin equivalent, Norton equivalent and Superposition are the techniques to analyze a circuit

Microelectronic Circuits, Sixth Edition Sedra/Smith Copyright © 2010 by Oxford University Press, Inc.

Signals and

Amplifiers

Microelectronics

-Discrete Components

-Integrated Circuits

Signal

• Schematic diagrams, block diagrams• DC (direct current)• ac (alternating current)


Figure 1.1 Two alternative representations of a signal source: (a) the Thévenin form (voltage); (b) the Norton form (current).

Signal

)()( tIRtv sss =


Figure 1.2 Circuits for Example 1.1.


Frequency Spectrum of Signals

)sin()( tVtv aa ω=

Time domain Frequency domain


Figure 1.5 A symmetrical square-wave signal of amplitude V (multiple sine waves).

Figure 1.6 The frequency spectrum (also known as the line spectrum) of the periodic square wave of Fig. 1.5.



Figure 1.7 The frequency spectrum of an arbitrary waveform



Figure 1.8 Sampling the continuous-time analog signal in (a) results in the discrete-time signal in (b).

Analog and Digital Signals


Figure 1.9 Variation of a particular binary digital signal with time.


Figure 1.11 (a) Circuit symbol for amplifier. (b) An amplifier with a common terminal (ground) between the input and output ports.

Amplifiers

- Output is usually larger than the input by factor A

- v0(t)=A.vin(t)

- Voltage gain (Av)=v0/vi


Amplifiersv0(t)=Avin(t)

Voltage gain (Av)=v0/vi

Voltage gain in decibels=20log|Av| dB

Power Gain (Ap)=PL/PI=v0i0/viiin

Power gain in decibels=10log|Ap| dB

Current Gain (Ai)=i0/iin

Current gain in decibels=20log|Ai| dB

Ap=AvAi


Figure 1.13 An amplifier that requires two DC supplies (shown as batteries) for operation.

100.(%)DC

L

PP

=η


Figure 1.14 An amplifier transfer characteristic that is linear except for output saturation.


Figure 1.15 Symbol convention employed throughout the book.

iC(t)=IC + ic(t)ic(t) =ICsin(ωt)

DC + ac

ac rides on top of DC


Figure 1.16 (a) Circuit model for the voltage amplifier. (b) The voltage amplifier with input signal source and load.

Circuit Models for Amplifiers

00 RR

RvAvL

Livo +

=

si

isi RR

Rvv

+=


Figure 1.18 Determining the output resistance


Cascaded Amplifiers


Figure 1.27 Use of a capacitor to couple amplifier stages.


Figure 1.20 Measuring the frequency response of a linear amplifier: At the test frequency ω , the amplifier gain is characterized by its magnitude

(Vo /Vi) and phase ø .

Frequency Response of Amplifiers


sCCjssLL

sVsV

sT

VV

T

i

i

1)()(

)(

)()(

)(

0

0

⇒=⇒

=

=

ω

ωω

ω


Figure 1.23 (a) Magnitude and (b) phase response of STC networks of the low-pass type.

Bode Plots

Phase Plots


Figure 1.26 Frequency response for (a) a capacitively coupled amplifier, (b) a direct-coupled amplifier, and (c) a tuned or bandpass

amplifier.

Classified of amplifiers based on frequency response


Important Concept: Voltage Divider

V1

V2

R1

R2

Summary


1. Components:A. Resistors: resist/impede current. Used to limit current, form voltage dividerB. Capacitors: store and release charges. Use as resistance for ac signals

(impedance) and block DC signal (allow ac signals passing through)C. Inductors: store and release magnetic field. Used as impedance for ac

signals, do not block DC signals.D. Diodes, transistors, op-amps are used to process the signals

2. SignalsA. Signal can be represented with Thevenin (voltage) or Norton (current) formB. Signal is a waveform versus time (or sum of sinusoids) with period (second)

and frequency (Hz)C. Analog signal has amplitude continuous with time, processed with analog

processingD. Digital signal has 2 possible amplitudes (high/logic 1 or low/logic 0)E. Analog signals and digital signals meet at the Analog Digital Converter

3. AmplifiersA. Increase signal power (voltage + current), require DC suppliesB. Have a gain (V/V or dB)C. Have a frequency response (gain versus frequency)D. Can have multiple amplifiers connected through coupling capacitors


Microelectronics

-Discrete Circuits

-Integrated Circuits

ee 221.3 t1 - 2016 - college of engineering 1_signals.pdf · – text book: "microelectronic...

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