MOTOROLA CMOS LOGIC DATA

MC14008B

42

Figure 6. Using the MC14008B in a 16–Bit Adder Configuration

WORD A + B INPUTS

A1

B4

A1

B4

A1

B4

A1

B4

S1

S4

S1

S4

S1

S4

S1

S4

Cin

Cin

Cin

Cin

Cout

Cout

Cout

Cout

CHIP

1

CHIP

2

CHIP

3

CHIP

4

SUM OUTPUTS

Calculation of 16–bit adder speed:

tP total = tP (Sum to Carry) + tP (Carry to Sum) + 2 tP (Carry to Carry)

The guaranteed 16–bit adder speed at 10 V, 25

°C, CL = 50 pF is:

tp total = 290 + 310 + 300 = 900 ns

TYPICAL APPLICATION