74F182PC Fairchild Semiconductor, 74F182PC Datasheet - Page 2

• Manufacturer Part Number: 74F182PC
• Description: IC GENERATOR LOOKAHEAD 16-DIP
• Manufacturer: Fairchild Semiconductor
• Series: 74Fr

Specifications of 74F182PC

• Logic Type: Look-ahead Carry Generator
• Supply Voltage: 4.5 V ~ 5.5 V
• Number Of Bits: 4
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 74F182

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Unit Loading/Fan Out
Functional Description
The 74F182 carry lookahead generator accepts up to four
pairs of Active LOW Carry Propagate (P
Generate (G
(C
C
74F182 also has Active LOW Carry Propagate (P) and
Carry Generate (G) outputs which may be used for further
levels of lookahead. The logic equations provided at the
outputs are:
*ALUs may be either 74F181 or 74F381
n y
n
) and provides anticipated Active HIGH carries (C
, C
C
C
C
G
P
n x
n y
n z
n z
P
G
2
3
) across four groups of binary adders. The
G
G
G
P
0
2
1
2
0
–G
P
C
G
G
G
P
P
P
C
G
P
P
3
n
0
2
3
n x
Pin Names
0
1
3
1
, P
3
P
P
P
, G
G
P
) signals and an Active HIGH Carry input
0
1
2
2
0
1
G
C
G
2
C
n
0
FIGURE 1. 32-Bit ALU with Rippled Carry between 16-Bit Lookahead ALUs
1
P
n z
3
P
P
P
1
2
2
P
P
G
0
1
1
Carry Input
Carry Generate Inputs (Active LOW)
Carry Generate Input (Active LOW)
Carry Generate Input (Active LOW)
Carry Propagate Inputs (Active LOW)
Carry Propagate Input (Active LOW)
Carry Propagate Input (Active LOW)
Carry Outputs
Carry Generate Output (Active LOW)
Carry Propagate Output (Active LOW)
C
G
n
0
P
3
P
P
2
2
P
P
1
1
0
P
G
–P
0
0
C
3
Description
) and Carry
n
n
x
,
2
Also, the 74F182 can be used with binary ALUs in an
active LOW or active HIGH input operand mode. The con-
nections (Figure 1) to and from the ALU to the carry looka-
head generator are identical in both cases. Carries are
rippled between lookahead blocks. The critical speed path
follows the circled numbers. There are several possible
arrangements for the carry interconnects, but all achieve
about the same speed. A 28-bit ALU is formed by dropping
the last 74F181 or 74F381.
HIGH/LOW
1.0/14.0
1.0/16.0
50/33.3
50/33.3
50/33.3
1.0/2.0
1.0/8.0
1.0/8.0
1.0/6.0
1.0/4.0
U.L.
Output I
20 A/ 1.2 mA
20 A/ 8.4 mA
20 A/ 9.6 mA
20 A/ 4.8 mA
20 A/ 4.8 mA
20 A/ 3.6 mA
20 A/ 2.4 mA
Input I
1 mA/20 mA
1 mA/20 mA
1 mA/20 mA
IH
OH
/I
/I
IL
OL