NDSU
35: Transistor Transistor Logic (TTL)
ECE 321  JSG
Transistor Transistor Logic (TTL)
An improved form of digital logic uses two transistors rather than a diode, and is termed Transistor
Transistor Logic (TTL). The basic circuit for a TTL inverter is
NDSU
11: AC to DC Converters
ECE 321  JSG
AC to DC Converters
Objective:
Convert 60Hz AC to a DC signal.
AC travels more efficiently over power grids than DC (transformers don't work at DC).
DC works better for microcontrollers. (They don't like being tu
NDSU
Diode Transistor Logic (DTL)
ECE 321  JSG
Diode Transistor Logic (DTL)
Logic AND operates sort of like a minimum function. The minimum voltage of all inputs is zero if any of
them are zero. It's 5V only if they all are 5V.
Logic OR operates sort of
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Semiconductor Relays
September 30, 2016
Semiconductor Relays (SCR)
AC to DC Conversion (take 2)
Thyristor (SCR):
A thyristor (or SCR) is a PNPN device, which can be thought of as a PNP and an NPN transistor strung
together:
A
A
Anode
Anode
p
p
n
n
n
NDSU
9: Clippers
ECE 321  JSG
Clippers & Clampers
Clipper Circuits:
Problem: Design a circuit which clips the voltage output at <6V using an ideal silicon diode.
Solution:
R
+
+
Vin
Vout
5.3V

Assume the diode is off. In this case, Vout = Vin.
Now, assu
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36: CMOS Logic
ECE 321  JSG
CMOS and BiCMOS Logic
TTL logic is used widely, but has a few limitations:
The input impedance is not infinity. This limits the fanout.
The corresponding power consumption is somewhat high (5mW computed previously).
CMOS
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Transistors
ECE 321  JSG
Transistors
NPN Transistor Theory
Transistors are similar to diodes in that they are made up on ntype and ptype silicon. They differ in that
Transistors are 3terminal devices (NPN or PNP),
Transistors can operate in three
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Max, Min Average Circuits
ECE 321  JSG
Max, Min, Average Circuits
Fuzzy Logic:
Fuzzy Logic is a type of logic which can deal with statements being partially true. For example, if
0.0V means false and
10.0V means true
then 5.0V means 50% true. With f
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33: Boolean Logic
ECE 321
Boolean Logic
Boolean logic lives in a blackandwhite world where everything is either true (logic 1) or false (logic 0).
There are other forms of logic, such as fuzzy logic, where things can be grey. That's for another cou
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H Bridges
ECE 321  JSG
HBridges
With a single NPN transistor, you can turn a motor on and off. If the motor only spins in one direction,
that's all you need. If you want to design a motor that can spin forward and backwards, you need an
Hbridge.
T
ECE 320  Homework #3
pn junction, Diode VI characteristics, Ideal Diodes. Due Monday January 30th, 2017
Problem 12) Use the following circuit:
200
10V
+
Vd

+

Id
1) Determine the voltage and current through the diode for the following circuit assumin
ECE 320  Homework #2
Phasors Review. Due Monday January 23rd, 2017
1a) Convert the following circuit to phasor notation
At DC (Vin = 15V)
At 60Hz (Vin = 2 sin(377t)
1b) Solve for y(t) using phasors.
2) Check your answer in PartSim.
0.5 H
y(t)
+
100
15 +
ECE 320  Homework #5
AC to DC Converters, DC to DC Converters. Due Monday February 13th, 2017
AC to DC Converter.
L
V1
V2
2Vpp
20Vp
60 Hz
20sin(377t)
0.5Vpp
Load
1000
C
+

1) Find L and C so that
V1 has a ripple of 2Vpp and
V2 has a ripple of 0.5Vpp
For
ECE 320  Homework #1
EE 206 Review. Due Wednesday, January 18th, 2017
1) Determine the resistance between notes A and B
200
100
300
A
100
300
200
100
200
300
B
Problem 1
Current Loops:
2) Write the current loop equations for the following circuit
3) Solv
ECE 320  Homework #2
Phasors Review. Due Monday January 23rd, 2017
1a) Convert the following circuit to phasor notation
0.5 H
j0
y(t)
j188.5
15+j0
+
100
15 + 2 sin(377t)

0j2
Phasor Representation of Circuit at w = 0 (red) and w = 377 (blue)
1b) Solve
ECE 320  Homework #1
EE 206 Review. Due Wednesday, January 18th, 2017
1) Determine the resistance between notes A and B
200
100
300
A
100
200
B
Problem 1
Starting on the right:
300 + 300 + 300 = 900 Ohms
900  200 = 163.63 Ohms
200 + 163.63 + 200 = 563.6
ECE 320  Homework #3
pn junction, Diode VI characteristics, Ideal Diodes. Due Monday January 30th, 2017
Problem 12) Use the following circuit:
200
10V
+

+
Vd

Id
1) Determine the voltage and current through the diode for the following circuit assumin
ECE 320  Homework #5
AC to DC Converters, DC to DC Converters. Due Monday February 13th, 2017
AC to DC Converter.
L
V1
V2
2Vpp
20Vp
60 Hz
20sin(377t)
+
0.5Vpp
C
Load
1000

1) Find L and C so that
V1 has a ripple of 2Vpp and
V2 has a ripple of 0.5Vpp
For
ECE 376  Homework #4
C vs. Assembler, LCD Display. Due Monday, February 20th
1) Write a C program which counts on PORTC. (barebones program)
#include <pic18.h>
void main(void)
cfw_
TRISC = 0;
ADCON1 = 0x0F;
while(1) cfw_
PORTC = PORTC + 1;
How many li
ECE 376  Homework #3
Flow Charts, Binary Inputs, Binary Outputs & Timing, LEDs. Due Monday, January 30th
Due Monday, February 6th
Binary Inputs: Assume the light sensor in your kits has a resistance / light relationship of
R
100,000
Lux
1) Design a circu
ECE 376  Homework #6
Stepper Motors and Analog Inputs. Due Friday, March 10th
(no homework over spring break)
1) Requirements.
Inputs
Potentiometer (0V to 5V on RA0)
Outputs:
Stepper motor connected to PORTC
Relationship:
When the A/D reading is less tha
ECE 463/663  Homework #1
LaPlace Transforms and Dominant Poles. Due Wednesday, Jan 18th
1) Name That System! Give the transfer function for a system with the following step response.
This is a 1storder system, so the answer is in the form of
G(s)
a
s+b
ECE 376  Homework #2
Assembler, Flow Charts. Due Monday, January 23rd
1) Convert the following C code to assembler:
; unsigned char A, B, C;
A
B
C
EQU
EQU
EQU
0
1
2
; A = 5;
movlw
movwf
5
A
; B = 6;
movlw
movwf
6
B
; C = A + B;
movf
addwf
movwf
A,W
B,W
C
ECE 461  Homework Set #7
Lead, PID, Systems with Delays. Due Monday October 20th
Problem 13) The transfer function for controlling the temperature at the tip of a metal bar is
300
Y s1s3s9s20 X
Gain Compensation: K(s) = k
1a) Design a gain comensator wh
Solution to Homework #6 ECE 461
Root Locus  Gain Compensation  Due Monday, October 13
Problem 14
50
Gs s1s3s6
1) Sketch the root locus for G(s) including
Real Axis Loci: (1, 3), (6, infinity)
Breakaway Point(s): s = 1.8802
d
s
ds
1s 3s 6 0
jw Cr
Homework #10 ECE 461
Due Monday, November 17th
Let G(s) be sampled at 100ms (T = 0.1):
50
G(s) = (s+1)(s+3)(s+10)
1) A discretetime model which approximates G(s) is G(z)
0.0273z 2
(z0.9)(z0.74)(z0.37)
1a) Draw the root locus for G(z)
1b) Find k for a
ECE 461  Homework Set #12
Gain, Lead, Lag Compensatio with Bode Plots. Due Monday, December 1st
1) For the following system:
500
G(s) = (s+1)(s+3)(s+9)
design a compensator, K(s), which results in
No error for a step input,
A 0dB gain frequency of 3 rad
ECE 461  Homework Set #11
Bode Plots, Nichols Charts, Gain Compensation in the Frequency Domain. Due Monday, November 24th
1) Name That System: Give the transfer function for a system with the following frequency response.
Draw in the straightline asymp