DYNAMIC ELECTRICAL CHARACTERISTICS (continued)

Symbol

Parameter

Test Conditions

Value

Unit

Min.

Typ.

Max.

Inhibit Input Removal Time

5

240

120

ns

10

130

65

15

110

55

Set Remova Time

5

150

75

ns

10

80

40

15

50

25

Clear Removal Time

5

60

30

ns

10

40

20

15

30

15

APPLICATION NOTE

For fractional multipliers with more than one digit,

HCC/HCF4527B devices may be cascated in two

different modes: the Add mode and the Mltiply mode

(see figures 1 and 2).

When two units are cascated in Add mode and pro-

grammed to 9 and 4 respectively, the more signifi-

cant unit will have 9 output pulses for every 10 input

pulses and the other unit will have 4 output pulses

for every 100 input pulses for a total of:

9

10

+

4

100

=

94

100

In the multiply mode, the fraction programmed into

the first rate multiplier is multiplied by the fraction

programmed into the second one:

4

10

=

9

10

=

4

10

× 



9

10







=

36

100

Therefore 36 output pulses for every 100 clock input

pulses.

HCC/HCF4527B

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