Date post: | 04-Apr-2018 |
Category: |
Documents |
Upload: | aaljuhani123 |
View: | 224 times |
Download: | 0 times |
of 36
7/29/2019 Signal Generators
1/36
EE 359 Electronic Circuits
November 2, 2007 0
Signal Generators
Oscillators
7/29/2019 Signal Generators
2/36
EE 359 Electronic Circuits
November 2, 2007 1
HW:
Due Friday Nov. 9 13.4,13.14,13.23,13.27
7/29/2019 Signal Generators
3/36
EE 359 Electronic Circuits
November 2, 2007 2
SIGNAL GENERATORS
/OSCILLATORSA positive-feedback
loop is formed by an
amplifier and afrequency-selective
network
In an actual oscillator circuit, no input signalwill be present
7/29/2019 Signal Generators
4/36
EE 359 Electronic Circuits
November 2, 2007 3
Oscillator-frequency stability
7/29/2019 Signal Generators
5/36
EE 359 Electronic Circuits
November 2, 2007 4
Limiter Ckt Comparator
7/29/2019 Signal Generators
6/36
EE 359 Electronic Circuits
November 2, 2007 5
Wien-bridge oscillator
without amplitudestabilization.
7/29/2019 Signal Generators
7/36
EE 359 Electronic Circuits
November 2, 2007 6
Wien bridge w/ Amp. Stabil.
limiter used for amplitude control.
7/29/2019 Signal Generators
8/36
EE 359 Electronic Circuits
November 2, 2007 7
Alternate Wien bridge stabil.
7/29/2019 Signal Generators
9/36
EE 359 Electronic Circuits
November 2, 2007 8
Phase Shift Oscillator
7/29/2019 Signal Generators
10/36
EE 359 Electronic Circuits
November 2, 2007 9
Phase Shift. Osc. W/ Stabil.
7/29/2019 Signal Generators
11/36
EE 359 Electronic Circuits
November 2, 2007 10
Quad Osc. Circuit
7/29/2019 Signal Generators
12/36
EE 359 Electronic Circuits
November 2, 2007 11
Active Tuned Osc.
7/29/2019 Signal Generators
13/36
EE 359 Electronic Circuits
November 2, 2007 12
OPAMP based Tuned Amp. Osc.
7/29/2019 Signal Generators
14/36
EE 359 Electronic Circuits
November 2, 2007 13
Colpitts and Hartley Oscillators
7/29/2019 Signal Generators
15/36
EE 359 Electronic Circuits
November 2, 2007 14
Equiv. Ckt
To simplify the analysis, negtlect Cm and rp
Consider Cp to be part ofC2, and include ro inR.
7/29/2019 Signal Generators
16/36
EE 359 Electronic Circuits
November 2, 2007 15
Collpits Oscillator
7/29/2019 Signal Generators
17/36
EE 359 Electronic Circuits
November 2, 2007 16
Piezzoelectric Crystal
7/29/2019 Signal Generators
18/36
EE 359 Electronic Circuits
November 2, 2007 17
Pierce Oscillator
CMOS inverter as an amplifier.
7/29/2019 Signal Generators
19/36
EE 359 Electronic Circuits
November 2, 2007 18
Bistable Operation
7/29/2019 Signal Generators
20/36
EE 359 Electronic Circuits
November 2, 2007 19
Bistable
7/29/2019 Signal Generators
21/36
EE 359 Electronic Circuits
November 2, 2007 20
7/29/2019 Signal Generators
22/36
EE 359 Electronic Circuits
November 2, 2007 21
Hysteresis
7/29/2019 Signal Generators
23/36
EE 359 Electronic Circuits
November 2, 2007 22
Noisy Signal
7/29/2019 Signal Generators
24/36
EE 359 Electronic Circuits
November 2, 2007 23
Limiter circuits = more precise output levels forbistable circuit.
R according to current required for the proper
operation of the zener diodes.
a) L+ = VZ1
+ VD andL=
(VZ2+ VD),
(b)L+ = VZ+ VD1+ VD2
andL=
(VZ+ VD3+ VD4
).Limiter
7/29/2019 Signal Generators
25/36
EE 359 Electronic Circuits
November 2, 2007 24
Abistable multivibrator with inverting transfer
characteristics in a feedback loop with an RC circuit
results in a square-wave generator.
Astable w/ feedback
7/29/2019 Signal Generators
26/36
EE 359 Electronic Circuits
November 2, 2007 25
The circuit obtained when
the bistable multivibrator is
implemented with the circuit
c) Waveforms at
various nodes of the
circuit in (b).
(This circuit is
called an
astable
multivibrator.)
Astable
Ckt f t i /
7/29/2019 Signal Generators
27/36
EE 359 Electronic Circuits
November 2, 2007 26
A general scheme for generating triangular and
square waveforms.
Ckt for triang/square wave
7/29/2019 Signal Generators
28/36
EE 359 Electronic Circuits
November 2, 2007 27
(a) An op-amp monostable circuit. (b) Signal
waveforms in the circuit of (a).
7/29/2019 Signal Generators
29/36
EE 359 Electronic Circuits
November 2, 2007 28
internal circuit of the 555 integrated-circuit timer.
555 IC
7/29/2019 Signal Generators
30/36
EE 359 Electronic Circuits
November 2, 2007 29
a) The 555 timer connected to implement a
monostable multivibrator. (b) Waveforms of the
circuit in (a).
555 for monostable
7/29/2019 Signal Generators
31/36
EE 359 Electronic Circuits
November 2, 2007 30
(a) The 555 timer connected to
implement an astable multivibrator.
(b) Waveforms of the circuit in (a).
555 for astable
7/29/2019 Signal Generators
32/36
EE 359 Electronic Circuits
November 2, 2007 31
Using a nonlinear
(sinusoidal) transfercharacteristic to shape
a triangular waveform
into a sinusoid.
Triangle Sinusoid
7/29/2019 Signal Generators
33/36
EE 359 Electronic Circuits
November 2, 2007 32
(a) A three-segment sine-wave shaper. (b) The input
triangular waveform and the output approximately
sinusoidal waveform.
7/29/2019 Signal Generators
34/36
EE 359 Electronic Circuits
November 2, 2007 33
A differential pair with anemitter degeneration
resistance used to
implement a triangular-
wave to sine-waveconverter.
S di d
7/29/2019 Signal Generators
35/36
EE 359 Electronic Circuits
November 2, 2007 34
(a) The superdiode precision half-wave rectifier and(b) its almost ideal transfer characteristic.
when vI> 0 and the diode conducts, the op amp supplies
the
load current, and the source is conveniently buffered,an added advantage.
Superdiode
7/29/2019 Signal Generators
36/36
EE 359 Electronic Circuits
November 2 2007 35
(a) An improved version of the precision half-wave rectifier:DiodeD2 is included to keep the feedback loop closed
around the op amp during the off times of the rectifier
diodeD1, thus preventing the op amp from saturating.
(b) Th t f h t i ti f R2 R1