Post on 02-Jan-2016
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-1
Logic Chips
HD
74
LS
04
P
1
2
3
4
5
6
7 8
9
10
11
12
13
14
HD74LS04P
Actual circuit is on a small chip of silicon
Package – Made of plastic or ceramic
Pins are connected to chip with internal wires
Pin number one is identified with a dot or notch
Pins are numbered in a counter-clockwise fashion
Standard chips use either TTL (Transistor-Transitor Logic), or CMOS transistors
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-2
Logic Chips – 7400 NAND
74L
S00
1
2
3
4
5
6
7 8
9
10
11
12
13
14
Part number – 74xx00 is a 7400 Quad Nand Gate
GND
Vcc
All chips have connections to Vcc (+5) and GND – Usually pins 14 and 7
There are four 2-input NAND gates in a 7400
LS – Low-Power Schottky TTLHC – CMOSHCT – TTL-compatible CMOSF – Fast TTL
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-3
Logic Chips – Inverters and NORs
1
2
3
4
5
6
7 8
9
10
11
12
13
14
GND
Vcc
74LS
04
1
2
3
4
5
6
7 8
9
10
11
12
13
14
GND
Vcc
74LS
02
74xx04 Hex Inverter 74xx02 Quad NOR Gate
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-4
Logic Families
5V TTL
Standard Low-Power Schottky – LSFast - F
5V CMOS
Standard - HCHCT – TTL compatible
0
5
4
3
2
1
Input Voltage
0
5
4
3
2
1
Output Voltage
0
5
4
3
2
1
Input Voltage
0
5
4
3
2
1
Output Voltage
High
Low
High
Low
High
Low
High
Low
WARNING – Don’t mix TTL and HC
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-5
Finding Info on Chips
• Search online
• Enter the part number, with family code
• “74LS02 datasheet”
• “74HC00 datasheet”
• Basic functionality is easy to find
• Timing info may require looking up the exact manufacturer
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-6
Making a logic circuit
12345678 9
10 11 12 13 14
GN
D
Vcc
74LS04 74LS00
12345678 9
10 11 12 13 14
GN
D
Vcc
A
C
AB
F
T1
T2
T1
T2
A
C
AB
F
GND
GND
+5 +5
AB C
F
T1
T2
Convert to NANDs
Seattle Pacific University EE 1210 - Logic System Design Standard Gates-7
Prototyping Breadboardsa
b c
d e
f g
h
i j
+-
+-
+-
+-
+/- Are connected in columns. Used for connections to +5V and GND.Note: On some boards, they are split in the middle
a/b/c/d/e and f/g/h/i/j are connected in rows. Used for connecting to chips. Note: They are not connected in the middle.
Connections for Power/GND Connections from chip to chip
74LS04 74LS02 74LS00To +6V