CMOS USAGE RULE
- Bipolar
- 74 – Standard TTL. the original logic family had no letters between the "74" and the part number. 10 ns gate delay, 10 mW dissipation, 4.75–5.25 V, released in 1966.[3]
- 74L – Low-power. Larger resistors allowed 1 mW dissipation at the cost of a very slow 33 ns gate delay. Obsolete, replaced by 74LS or CMOS technology. Introduced 1971.[20]
- 74H – High-speed. 6 ns gate delay but 22 mW power dissipation. Used in 1970s era supercomputers. Still produced but generally superseded by the 74S series. Introduced in 1971.
- 74S – High-speed Schottky. Implemented with Schottky diode clamps at the inputs to prevent charge storage, this provides faster operation than the 74 and 74H series at the cost of increased power consumption and cost. 3 ns gate delay, 20 mW dissipation, released in 1971.
- 74LS – Low-power Schottky. Implemented using the same technology as 74S but with reduced power consumption and switching speed. Typical 10 ns gate delay, a remarkable (for the time) 2 mW dissipation, 4.75–5.25 V.
- 74AS – Advanced Schottky, the next iteration of the 74S series with greater speed and fan-out despite lower power consumption. Implemented using the 74S's technology with "miller killer" circuitry to speed up the low-to-high transition. 1.7 ns gate delay, 8 mW, 4.5–5.5 V.
- 74ALS – Advanced low-power Schottky. Same technology as 74AS but with the speed/power tradeoff of the 74LS. 4 ns, 1.2 mW, 4.5–5.5 V.
- 74F – Fast. Fairchild's version of TI's 74AS. 3.4 ns, 6 mW, 4.5–5.5 V. Introduced in 1978.
- CMOS
- C – CMOS 4–15 V operation similar to buffered 4000 (4000B) series.
- HC – High-speed CMOS, similar performance to 74LS, 12 ns. 2.0–6.0 V.
- HCT – High speed, compatible logic levels to bipolar parts.
- AC – Advanced CMOS, performance generally between 74S and 74F.
- ACT – Advanced CMOS, performance generally between 74S and 74F. Compatible logic levels to bipolar parts.
- ACQ – Advanced CMOS with Quiet outputs.
- AHC – Advanced high-speed CMOS, three times as fast as 74HC, tolerant of 5.5V on input.
- ALVC – Low-voltage – 1.8–3.3 V, time Propagation Delay (TPD) < 3 ns at 3.3 V.
- ALVT – Low-voltage – 2.5–3.3 V, 5 V tolerant inputs, high current ≤ 64 mA, TPD < 3 ns at 2.5 V.
- AUC – Low-voltage – 0.8–2.5 V, TPD < 2.5 ns at 1.8 V.
- AUP – Low-voltage – 0.8–3.6 V (3.3 V typically), TPD 15.6/8.2/4.3 ns at 1.2/1.8/3.3V, partial power-down specified (IOFF), inputs protected.
- AVC – Low-voltage – 1.2–3.3 V, TPD < 3.2 ns at 1.8 V, bus hold, IOFF.[21]
- AXC – Low-voltage – 0.65–3.6 V, TPD < 3.2 ns at 1.8 V, bus hold, IOFF.[22]
- FC – Fast CMOS, performance similar to 74F.
- LCX – CMOS with 3 V supply and 5 V tolerant inputs.
- LV – Low-voltage CMOS – 2.0–5.5 V supply and 5 V tolerant inputs.
- LVC – Low voltage – 1.65–3.3 V and 5 V tolerant inputs, TPD < 5.5 ns at 3.3 V, TPD < 9 ns at 2.5 V.
- LV-A – 2.5–5 V, 5 V tolerant inputs, TPD < 10 ns at 3.3 V, bus hold, IOFF, low noise.
- LVT – Low-voltage – 3.3 V supply, 5 V tolerant inputs, high output current < 64 mA, TPD < 3.5 ns at 3.3 V, IOFF, low noise.
- LVQ – Low-voltage – 3.3 V.
- LVX – Low-voltage – 3.3 V with 5 V tolerant inputs.
- VHC – Very-high-speed CMOS – 74S performance in CMOS technology and power.
- BiCMOS
- BCT – BiCMOS, TTL-compatible input thresholds, used for buffers.
- ABT – Advanced BiCMOS, TTL-compatible input thresholds, faster than 74ACT and 74BCT.
Many parts in the CMOS HC, AC, and FC families are also offered in "T" versions (HCT, ACT, and FCT) which have input thresholds that are compatible with both TTL and 3.3 V CMOS signals. The non-T parts have conventional CMOS input thresholds.
The 74H family is the same basic design as the 7400 family with resistor values reduced. This reduced the typical propagation delay from 9 ns to 6 ns but increased the power consumption. The 74H family provided a number of unique devices for CPU designs in the 1970s. Many designers of military and aerospace equipment used this family over a long period and as they need exact replacements, this family is still produced by Lansdale Semiconductor.[23]
The 74S family, using Schottky circuitry, uses more power than the 74, but is faster. The 74LS family of ICs is a lower-power version of the 74S family, with slightly higher speed but lower power dissipation than the original 74 family; it became the most popular variant once it was widely available.
The 74F family was introduced by Fairchild Semiconductor and adopted by other manufacturers; it is faster than the 74, 74LS and 74S families.
Through the late 1980s and 1990s newer versions of this family were introduced to support the lower operating voltages used in newer CPU devices.
Characteristics of selected 7400 series families[24]
Parameter
|
74C
|
74HC
|
74AC
|
74HCT
|
74ACT
|
Units
|
(VDD = 5 V)
|
VIH (min)
|
3.5
|
2.0
|
V
|
VOH (min)
|
4.5
|
4.9
|
V
|
VIL (max)
|
1.5
|
1.0
|
1.5
|
0.8
|
V
|
VOL (max)
|
0.5
|
0.1
|
V
|
IIH (max)
|
1
|
μA
|
IIL (max)
|
1
|
μA
|
IOH (max)
|
0.4
|
4.0
|
24
|
4.0
|
24
|
mA
|
IOL (max)
|
0.4
|
4.0
|
24
|
4.0
|
24
|
mA
|
TP (max)
|
50
|
8
|
4.7
|
8
|
4.7
|
ns
|
List of 4000-series integrated circuits"
List of 7400-series integrated circuits"
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