oscillator design.ppt
TRANSCRIPT
-
8/18/2019 Oscillator design.ppt
1/56
ECES 352 Winter 2007
Oscillator
-
8/18/2019 Oscillator design.ppt
2/56
ECES 352 Winter 2007
Objectives
* Describe the basic concept of an oscillator
* Discuss the basic principles of operation of an oscillator
* Analyze the operation of RC and LC oscillators
* Describe the operation of the basic relaxation oscillator circuits
-
8/18/2019 Oscillator design.ppt
3/56
ECES 352 Winter 2007
Introduction
* Oscillator is an electronic circuit that generates a periodic avefor!
on its output ithout an external signal source" It is used to convert dc
to ac"* Oscillators are circuits that produce a continuous signal of so!e type
ithout the need of an input"
* #hese signals serve a variety of purposes"
* Co!!unications syste!s$ digital syste!s %including co!puters&$ and
test e'uip!ent !a(e use of oscillators
-
8/18/2019 Oscillator design.ppt
4/56
ECES 352 Winter 2007
Introduction
* An oscillator is a circuit that produces a repetitive signal
fro! a dc voltage"
* #he feedbac( oscillator relies on a positive feedbac( of
the output to !aintain the oscillations"
* #he relaxation oscillator !a(es use of an RC ti!ing
circuit to generate a nonsinusoidal signal such as s'uareave
Sinewave
Squarewave
Sawtoothwave
-
8/18/2019 Oscillator design.ppt
5/56
ECES 352 Winter 2007
#ypes of oscillators
)" RC oscillators
ien +ridge
,hase-.hift
/" LC oscillators
0artley
Colpitts
Crystal1" 2nijunction 3 relaxation oscillators
-
8/18/2019 Oscillator design.ppt
6/56
ECES 352 Winter 2007
+asic principles for oscillation
* An oscillator is an a!plifier ith positive feedbac("
(1) f se V V V +=
(2) o f βV V =( ) ( ) (3) os f seo βV V AV V A AV V +=+==
-
8/18/2019 Oscillator design.ppt
7/56
ECES 352 Winter 2007
+asic principles for oscillation
* #he closed loop gain is4
( ) ( )os f seo
βV V AV V A AV V
+=+==
oso V A AV V β +=( ) so AV V A =− β 1
( ) Aβ A
V
V A
s
o f −
=≡1
-
8/18/2019 Oscillator design.ppt
8/56
ECES 352 Winter 2007
+asic principles for oscillation
* In general A and β are functions of fre'uency and thus !ay be rittenas5 is (non as loop gain
( ) ( ) ( )
( ) ( )s β s A1
s As
V
V s A
s
o f
−==
( ) ( )s β s A
-
8/18/2019 Oscillator design.ppt
9/56
ECES 352 Winter 2007
+asic principles for oscillation
* riting the loop gain beco!es5
* Replacing s ith jω
* and
( ) ( ) ( ) s s β AsT =
( ) ( )
( )sT 1s A
s A f −=
( ) ( )
( ) jωT 1
jω A jω A
f −=
( ) ( ) ( ) jω β jω A jωT =
-
8/18/2019 Oscillator design.ppt
10/56
ECES 352 Winter 2007
+asic principles for oscillation
* At a specific fre'uency f 6
* At this fre'uency$ the closed loop gain5
ill be infinite$ i"e" the circuit ill have finite output for zero input
signal - oscillation
( ) ( ) ( ) 1000 == jω β jω A jωT
( )
( )
( ) ( )00
0
0 jω β jω A1
jω A
jω A f −=
-
8/18/2019 Oscillator design.ppt
11/56
ECES 352 Winter 2007
+asic principles for oscillation
* #hus$ the condition for sinusoidal oscillation of fre'uency is f 6
* #his is (non as +ar(hausen criterion"
* #he fre'uency of oscillation is solely deter!ined by the phase
characteristic of the feedbac( loop 7 the loop oscillates at the
fre'uency for hich the phase is zero"
( ) ( ) 100 = jω β jω A
-
8/18/2019 Oscillator design.ppt
12/56
ECES 352 Winter 2007
+asic principles for oscillation
* #he feedbac( oscillator is idely used for generation of sine ave
signals"
* #he positive %in phase& feedbac( arrange!ent !aintains theoscillations"
* #he feedbac( gain !ust be (ept to unity to (eep the output fro!
distorting"
-
8/18/2019 Oscillator design.ppt
13/56
ECES 352 Winter 2007
+asic principles for oscillation
-
8/18/2019 Oscillator design.ppt
14/56
ECES 352 Winter 2007
Design Criteria for Oscillators
)" #he !agnitude of the loop gain !ust be unity or slightly larger
7 +ar(haussen criterion
/" #otal phase shift$φ of the loop gain !us t be 8x196: here 8;6$ )$/$ <
1= Aβ
-
8/18/2019 Oscillator design.ppt
15/56
ECES 352 Winter 2007
RC Oscillators
* RC feedbac( oscillators are generally li!ited to fre'uencies of ) =0z
or less"
* #he types of RC oscillators that e ill discuss are the ien-bridge
and the phase-shift
-
8/18/2019 Oscillator design.ppt
16/56
ECES 352 Winter 2007
ien-bridge Oscillator
* It is a lo fre'uency oscillator hich ranges fro! a fe (0z to )
=0z"
-
8/18/2019 Oscillator design.ppt
17/56
ECES 352 Winter 2007
ien-bridge Oscillator
* #he loop gain for the oscillator is5
* here5
* and5
( ) ( ) ( )
+
+==
s p
p
Z Z
Z
R
Rs β s AsT
1
21
sRC
R Z p +
=1
sC
sRC Z s
+= 1
-
8/18/2019 Oscillator design.ppt
18/56
ECES 352 Winter 2007
ien-bridge Oscillator
* 0ence5
* .ubstituting for s5
* >or oscillation fre'uency f 65
( )( )
++
+=
RC /j RC j R
R jT
66)
/6
)1
))
ω ω ω
( )
( )
++
+=
/sRC sRC R
RsT
13
11
1
2
( )
( )
++
+=
RC /j RC j R
R jT
ω ω
ω
)1
))
)
/
-
8/18/2019 Oscillator design.ppt
19/56
ECES 352 Winter 2007
ien-bridge Oscillator
* .ince at the fre'uency of oscillation$ T % jω & !ust be real %for zero phase condition&$ the i!aginary co!ponent !ust be zero5
* hich gives us5
6)
6
6 =+ RC j
RC jω
ω
RC
)6 =ω
-
8/18/2019 Oscillator design.ppt
20/56
ECES 352 Winter 2007
ien-bridge Oscillator
* >ro! the previous e'uation5
* the !agnitude condition is5
or
+=
1
)))
)
/
R
R
( )( )
++
+=
RC /j RC j R
R jT
66)
/6
)1
))
ω ω ω
/
)
/ =
R
R
To ensure oscillation, the ratio R2/ R1 must be
slightl greater than 2!
-
8/18/2019 Oscillator design.ppt
21/56
ECES 352 Winter 2007
ien-bridge Oscillator
* ith the ratio5
* then5
K ; 1 ensures the loop gain of unity 7 oscillation K ? 1 4 groing oscillations
K @ 1 4 decreasing oscillations
/)
/ = R
R
1))
/ =+≡ R
R K
-
8/18/2019 Oscillator design.ppt
22/56
ECES 352 Winter 2007
,hase-.hift Oscillator
* #he phase shift oscillator utilizes three RC circuits to provide )6B
phase shift that hen coupled ith the )6B of the op-a!p itself
provides the necessary feedbac( to sustain oscillations"* #he gain !ust be at least / to !aintain the oscillations"
* #he fre'uency of resonance for the this type is si!ilar to any RC
circuit oscillator4
RC f r
9/
)
π =
-
8/18/2019 Oscillator design.ppt
23/56
ECES 352 Winter 2007
,hase-.hift Oscillator
vi v
1v
1
v
2 v
2
v
3 v
o
C C
C
R R
R R2
iv
sRC
sRC v
+
=)
)
iv sRC
sRC v
/
/)
+=
iv
sRC
sRC v
1
1
)
+
=
1
1
)&%
+==
sRC
sRC s
v
v
i
β
R R
vv s A o /
1
&% ==
-
8/18/2019 Oscillator design.ppt
24/56
ECES 352 Winter 2007
,hase-.hift Oscillator
* Loop gain$ #%s&4
* .et s;j
1
/
)&%&%&%
+
==
sRC
sRC
R
R s s A sT β
[ ] [ ]///////
/
1
/
11)&&%%&%
)&%
C R RC jC R RC RC j
R R jT
RC j
RC j
R
R jT
ω ω ω ω ω ω
ω
ω ω
−+−
−=
+
=
-
8/18/2019 Oscillator design.ppt
25/56
ECES 352 Winter 2007
,hase-.hift Oscillator
* #o satisfy condition #%jo&;)$ real co!ponent !ust be zero since the
nu!erator is purely i!aginary"
* the oscillation fre'uency4
* Apply o in e'uation4
* #o satisfy condition #%jo&;)
61) /// =− C Rω
RC 1
)
6 =ω
[ ]
−=
−+
−=
A
)
&13)%1&13%6
&13)&%13%&% //
R
R
j
j
R
R jT oω
A/ =
R
R The gain greater than ", the circuit #ills$ontaneousl begin oscillating % sustain
oscillations
-
8/18/2019 Oscillator design.ppt
26/56
ECES 352 Winter 2007
,hase-.hift Oscillator
RC f o
9/
)
π = // =
R
RThe gain must be at least
2& to maintain the
oscillations
-
8/18/2019 Oscillator design.ppt
27/56
ECES 352 Winter 2007
LC Oscillators
* 2se transistors and LC tuned circuits or crystals in their feedbac(
netor("
* >or hundreds of (0z to hundreds of =0z fre'uency range"* xa!ine Colpitts$ 0artley and crystal oscillator"
-
8/18/2019 Oscillator design.ppt
28/56
ECES 352 Winter 2007
Colpitts Oscillator
* #he Colpitts oscillator is a type
of oscillator that uses an LCcircuit in the feed-bac( loop"
* #he feedbac( netor( is !ade
up of a pair of tapped tapped capacitorscapacitors
(C (C 11 and C and C 22 ) ) and an inductor Lan inductor L to produce a feedbac( necessary
for oscillations"
* #he output voltage is developed
across C)"
* #he feedbac( voltage is
developed across C/"
-
8/18/2019 Oscillator design.ppt
29/56
ECES 352 Winter 2007
Colpitts Oscillator
* ECL at the output node4
* voltage divider produces4
* substitute e'%/& into e'%)&4
6))
/)
=+
+++
sC sL
V V g RV
sC
V o gsm
oo
o gs V
sL sC
sC V •
+=
/
/
)
)
( ) 6)) )//
/ =
++++ sC R
LC s sC g V mo
- ' %)&
- ' %/&
-
8/18/2019 Oscillator design.ppt
30/56
ECES 352 Winter 2007
Colpitts Oscillator
* Assu!e that oscillation has started$ then FoG6
* Let s;jH
* both real i!aginary co!ponent !ust be zero I!aginary co!ponent4
( ) 6)
/)
/
/
/)
1
=
+++++ R g C C s R LC s
C LC s m
( )[ ] 6) /)//)//
=−++
++ C LC C C j
R
LC
R g m ω ω
ω
+
=
/)
/)
)
C C
C C
L
oω - ' %1&
-
8/18/2019 Oscillator design.ppt
31/56
ECES 352 Winter 2007
Colpitts Oscillator
* both real i!aginary co!ponent !ust be zero
I!aginary co!ponent4
* Co!bining '%1& and '%J&4
* to initiate oscillations spontaneously4
R g
R LC m )
/
/
+=ω
R g C
C m=
)
/
>
)
/
C
C R g m
- ' %J&
-
8/18/2019 Oscillator design.ppt
32/56
ECES 352 Winter 2007
0artley Oscillator
* #he 0artley oscillator
is al!ost identical tothe Colpitts oscillator"
* #he pri!ary
difference is that the
feedbac( netor( of
the 0artley oscillator
uses tapped tapped inductorsinductors
(L(L11 and Land L22 ) ) and aa single capacitor C single capacitor C "
-
8/18/2019 Oscillator design.ppt
33/56
ECES 352 Winter 2007
0artley Oscillator
* the analysis of 0artley oscillator is identical to that Colpitts oscillator"
* the fre'uency of oscillation4
( )C L Lo
/)
)
+=ω
-
8/18/2019 Oscillator design.ppt
34/56
ECES 352 Winter 2007
Crystal Oscillator
* =ost co!!unications and digital applications re'uire the
use of oscillators ith extre!ely stable outputextre!ely stable output" Crystal
oscillators are invented to overco!e the output fluctuationoutput fluctuation experienced by conventional oscillators"
* Crystals used in electronic applications consist of a 'uartz
afer held beteen to !etal plates and housed in a a
pac(age as shon in >ig" %a& and %b&"
-
8/18/2019 Oscillator design.ppt
35/56
ECES 352 Winter 2007
Crystal Oscillator
* ,iezoelectric ffect
#he 'uartz crystal is !ade of silicon oxide %.iO/& and exhibits a
property called the pieoelectric pieoelectric
hen a changing an alternating voltage is applied across the
crystal$ it vibrates at the fre'uency of the applied voltage" In the
other ord$ the fre'uency of the applied ac voltage is e'ual to the
natural resonant fre'uency of the crystal"
#he thinner the crystal$ higher its fre'uency of vibration" #his
pheno!enon is called piezoelectric effect"
-
8/18/2019 Oscillator design.ppt
36/56
ECES 352 Winter 2007
Crystal Oscillator
* Characteristic of Kuartz Crystal
#he crystal can have to resonant
fre'uencies5
One is the series resonance fre'uency f )
hich occurs hen L ; C" At this
fre'uency$ crystal offers a very loi!pedance to the external circuit here M
; R"
#he other is the parallel resonance %or
antiresonance& fre'uency f / hich occurs
hen reactance of the series leg e'ualsthe reactance of C=" At this fre'uency$
crystal offers a very high i!pedance to
the external circuit
R
L
C
CM
-
8/18/2019 Oscillator design.ppt
37/56
ECES 352 Winter 2007
Crystal Oscillator
* #he crystal is connected as a series ele!ent in the feedbac( path fro!
collector to the base so that it is excited in the series-resonance !ode
BJ
T FE
T
l ill
-
8/18/2019 Oscillator design.ppt
38/56
ECES 352 Winter 2007
Crystal Oscillator
* .ince$ in series resonance$ crystal i!pedance is the s!allest that
causes the crystal provides the largest positive feedbac("
* Resistors R )$ R /$ and R D provide a voltage-divider stabilized dc
bias circuit" Capacitor CD provides ac bypass of the e!itter
resistor$ R D to avoid degeneration"
* #he R>C coil provides dc collector load and also prevents any
ac signal fro! entering the dc supply"
* #he coupling capacitor CC has negligible reactance at circuit
operating fre'uency but bloc(s any dc flo beteen collector
and base"
* #he oscillation fre'uency e'uals the series-resonance fre'uency
of the crystal and is given by4
C
o LC
f π /
)=
2 ij i O ill
-
8/18/2019 Oscillator design.ppt
39/56
ECES 352 Winter 2007
2nijunction Oscillator
* #he unijunction transistor
can be used in hat is
called a rela!ationrela!ationoscillator oscillator as shon by
basic circuit as follo"
* #he unijunction oscillator
provides a pulse signal
suitable for digital-circuit
applications"
* Resistor R # and capacitor
C# are the ti!ing
co!ponents that set the
circuit oscillating rate
UJ
T
2 ij i O ill
-
8/18/2019 Oscillator design.ppt
40/56
ECES 352 Winter 2007
2nijunction Oscillator
* .atooth ave
appears at the e!itter
of the transistor"
* #his ave shos the
gradual increase of
capacitor voltage
2 ij i O ill
-
8/18/2019 Oscillator design.ppt
41/56
ECES 352 Winter 2007
2nijunction Oscillator
* #he oscillating fre'uency is calculated as follos4
* here$ N ; the unijunction transistor intrinsic stand- off ratio
* #ypically$ a unijunction transistor has a stand-off ratio fro! 6"J to 6"9
( )[ ]η −≅ )3)ln)
T T
oC R f
O ill
-
8/18/2019 Oscillator design.ppt
42/56
ECES 352 Winter 2007 '2
Oscillators
* eebac* am$li+ier but +reuenc e$enent +eebac*
* -ositi.e +eebac*, i!e! + ( ) ( ) 0
* scillator gain e+ine b
* scillation conition at 4 o (ar*hausen6s criterion) + (o) 4
( ) ( )
&%&%) s A s
s A s A
f
f β +
=
&%&%&%
)&%&%&%&%&%&%
oo f o
joo f oo f o
Aof p"ase
e A A L o
ω ω β ω φ
ω ω β ω ω β ω ω φ
=
===
( ) ( )
&%&%) s A s
s A s A
f
f β −=
i + id O ill t
-
8/18/2019 Oscillator design.ppt
43/56
ECES 352 Winter 2007 '3
ien +ridge Oscillator
* ase on o$ am$
* Combination o+ 6s an C6s in
+eebac* loo$ so +eebac* +actor+ has a +reuenc e$enence!
* nalsis assumes o$ am$ is ieal!
8ain is .er large
9n$ut currents are negligibl
small (9: 9; 0)! 9n$ut terminals are .irtuall
shorte (etermine +eebac* +actor!
>etermine gain #ith +eebac*!
* Shunt?shunt con+iguration!
-
8/18/2019 Oscillator design.ppt
44/56
ECES 352 Winter 2007 ''
ien +ridge Oscillator
-
8/18/2019 Oscillator design.ppt
45/56
ECES 352 Winter 2007 '5
ien +ridge Oscillator
@1
-
8/18/2019 Oscillator design.ppt
46/56
ECES 352 Winter 2007 'B
ien +ridge Oscillator
( )
r f
r rf
r r f
A
A A
sCR sCR
sCR
R
R
sCR sCR
sCR R
R
R
sCR
sC
A sCR
sC A
β
β
+=
++
+−=
+++
+
+−=
+−=
)
isfeedbac(ain ith
&)%)
&)%
))
)
)
/)
/
/)
/
Aoo$ 8ain
scillation conition
( )
/)1
))
usingelyappropriat
and resistors theselecting by)getcane#hen$
)
fre'uencynoscillatio at the 6ter!i!aginary#hen
)1
))
)1
))1)
)
/))
&)%)
Reriting
)&)%)onlyneed#hen
6" since isalreadyIt")A6 toe'ual of ,hase
)
/
)
/
/)
)
/
)
/
///
)
/
///
)
/
/
)
/
/
)
/
o
==
+
=
==
=
−+
+=
++
+=
++
+=
+++
+=
++
+=
=++
+=
<
R
Ror
R
R
R R A
RC
CRCR j
R
R
sCR sCR
R
R
RC s sCR
sCR
R
R
RC s sCR sCR
sCR
R
R
sCR sCR
sCR
R
R A
sCR sCR
sCR
R
R A
A A
r f
o
r f
r f
r f r f
β
ω ω
ω ω
β
β
β β
i + id O ill t l
-
8/18/2019 Oscillator design.ppt
47/56
ECES 352 Winter 2007 '7
ien +ridge Oscillator - xa!ple
scillator s$eci+ications o41D10B ra/s
K K R
K
srad !n C R
RC n C
o
o
/6&)6%/
get eR /R sincethen$)6R Choosing
)66&3)6)%)6
))
) fro!then$)6 econveniencfor.electing
/
)/)
9
====
Ω===
==
ω
ω
i + id O ill t
-
8/18/2019 Oscillator design.ppt
48/56
ECES 352 Winter 2007 '"
ien +ridge Oscillator
inal note No input signal is needed. oise at the esire oscillation +reuenc
#ill li*el be $resent at the in$ut an #hen $ic*e u$ b the oscillator #hen
the >C $o#er is turne on, it #ill start the oscillator an the out$ut #ill
uic*l builu$ to an acce$table le.el!
ien +ridge Oscillator
-
8/18/2019 Oscillator design.ppt
49/56
ECES 352 Winter 2007 '&
ien +ridge Oscillator* nce oscillations start, a limiting circuit is neee to $re.ent
them +rom gro#ing too large in am$litue
,hase .hift Oscillator
-
8/18/2019 Oscillator design.ppt
50/56
ECES 352 Winter 2007 50
,hase .hift Oscillator
* ase on o$ am$ using in.erting in$ut
* Combination o+ 6s an C6s in
+eebac* loo$ so get aitional $hase
shi+t! Target 1"0o to get oscillation!
* nalsis assumes o$ am$ is ieal!
-
8/18/2019 Oscillator design.ppt
51/56
ECES 352 Winter 2007 51
R R
so R
R
C R
RRC RRC
* RRC
) L(*
so ) L(*
RC so
CRCR
CRCR j
RRC
CRCR j
CR j
sCR sCR
sCR
V
V A L
sCR sCR sCR
V
f
f f f
o
f
o
o
f f
f
f
o
)/
))/1
)
JJ
get eforngsubstituti and)J
)need also ens$oscillatioget#o
1
))1
so fre'uencyoneatthisachievecan*e
zero" togo toter!i!aginarytheneed ens$oscillatioget#o
)
1J&%
)J
1
)
&%
)J1
&%&%&%
gain loop for thegete
&%
)J1F
gRearrangin
//
///
6
//
6
6
o
//
/
/
6
/
=
===
==
=
===
−+
=
−−
−=
=
++
−===
++−=
ω
ω
ω ω ω
ω
ω
ω ω
ω
ω ω
ω
ω ω β ω
,hase .hift Oscillator
-
8/18/2019 Oscillator design.ppt
52/56
ECES 352 Winter 2007 52
Colpitts LC-#uned Oscillator
* >eedbac( a!plifier ith inductor L andcapacitors C) and C/ in feedbac( netor("
>eedbac( is fre'uency dependent" Ai! to adjust co!ponents to get
positive feedbac( and oscillation"
Output ta(en at collector Fo"
8o input needed$ noise at oscillation
fre'uency ωo is pic(ed up anda!plified"
* R +) and R +/ are biasing resistors"
* R>C is R> Cho(e %inductor& to allo dccurrent flo for transistor biasing$ but to
bloc( ac current flo to ac ground"* .i!plified circuit shon at !idband
fre'uencies here large e!itter bypasscapacitor C and base capacitor C+ are
shorts and transistor capacitances %Cπ andCµ& are opens"
C+
C
-
8/18/2019 Oscillator design.ppt
53/56
ECES 352 Winter 2007 53
Colpitts LC-#uned Oscillator *
-
8/18/2019 Oscillator design.ppt
54/56
ECES 352 Winter 2007 5'
Colpitts LC-#uned Oscillator
* #o get oscillations$ both the real and i!aginary parts
of this e'uation !ust be set e'ual to zero"
* >ro! the i!aginary part e get the expression for
the oscillation fre'uency
* >ro! the real part$ e get the condition on the ratio
of C/3C)
( )[ ] 6) /)1
/)/
/
=−++
−+ C LC C C j
R LC
R g m ω ω ω
( )
+
=+=
=−+
/)
/)/)
/)
/)1
/)
)
6
C C
C C L
C LC
C C
C LC C C
o
oo
ω
ω ω
R g C
C
C
C
C LC
C C LC LC R g
R LC
R g
m
om
om
=
+=
+==+
=−+
)
/
)
/
/)
/)//
/
/
/
))
6)
ω
ω
Colpitts LC #uned Oscillator
-
8/18/2019 Oscillator design.ppt
55/56
ECES 352 Winter 2007 55
Colpitts LC-#uned Oscillator
* iven4
Design oscillator at )Q6 =0z
#ransistor g! ; )66 !A3F$ R ; 6"Q E
* Design4
.elect L; Q6 n0$ then calculate C/$ and then C)
( ) srad ! ! f o 3)6J")6)Q6// A9 === π π ω
Q6&Q"6&%3)66%)
/ === K V mA R g C C
m
p p C
C
p ! !n+ C
C
LC
C
C
LC C LC
C C
o
o
/1Q6
)16$)
Q6
)16$))6)1")&Q6)%&)6J"%Q6
))
)
))
/)
/A)
///
)
/
//)
/)
===
==+=
+=
+=
+=
−
ω
ω
xa!ple
.u!!ary of Oscillator Design
-
8/18/2019 Oscillator design.ppt
56/56
.u!!ary of Oscillator Design
* Sho#n ho# +eebac* can be use #ithreacti.e com$onents (ca$acitors) in the+eebac* $ath!
* Can be use to achie.e $ositi.e +eebac*! With a$$ro$riate choice o+ the resistor
si=es, can get +eebac* signal in $hase#ith the in$ut signal!
esulting circuit can $rouce largeam$litue sinusoial oscillations!
* >emonstrate three oscillator circuits Wien rige oscillator -hase Shi+t oscillator Col$itts AC?Tune oscillator
* >eri.e euations +or calculating resistor anca$acitor si=es to $rouce oscillations at theesire oscillator +reuenc!
* He result scillator esign e$ens$rimaril on com$onents in +eebac*net#or*, i!e! not on the am$li+ier6scharacteristics!
Wien rige scillator
-hase Shi+t scillator
Col$itts AC?Tune scillator