Transistor Transistor Logic (TTL) Properties

• 5 volt supply
• Unconnected inputs float "high" (logic level 1)
• Logic level 0 is represented by an output voltage between 0 and 0.5 volts.
• Logic level 1 is represented by an output between 2.7 to 5 volts.
• There is good noise immunity because of the wide voltage bands representing 0 and 1.
• One output can drive up to ten inputs (fan out).
• Operation up to 50MHz is possible.
• TTL has quite a high power consumption.
• The gates are robust and not easily damaged by static electricity. (Some variants are more sensitive)
• The 74LS family has lower power consumption.
• The 54 series chips operate over a wider temperature range.
• 4000 series CMOS gates have a much lower power consumption but these are easily damaged by static electricity.

74 Series on Wikipedia

Chip	Type	Pin-out		Chip	Type	Pin-out
Basic Two Input Gates
7400	Quad NAND A B Out 0 0 1 0 1 1 1 0 1 1 1 0			7402	Quad NOR A B Out 0 0 1 0 1 0 1 0 0 1 1 0
7404	Hex Inverter A Out 0 1 1 0			7408	Quad AND A B Out 0 0 0 0 1 0 1 0 0 1 1 1
7414	Hex Inverting Schmitt Trigger
7432	Quad OR A B Out 0 0 0 0 1 1 1 0 1 1 1 1			7486	Quad XOR A B Out 0 0 0 0 1 1 1 0 1 1 1 0
Flip Flops
7474	Dual D Type Flip Flop One Two				SR Latch
	Gated SR Latch
Counters
7490	Decade Counter Resets on 10			7493	Binary Counter Resets on 16
7447	BCD to 7 Segment Display Decoder Use common anode displays.			14.2mm 7 Seg Display	Kingbright SC56-11EWA JPR code 860-461