HCF4527B

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APPLICATION NOTE :

For fractional multipliers with more than one digit,

HCF4527B may be cascaded in two different

modes: The ADD mode and the MULTIPLY mode

(see figure 1 and 2).

When two units are cascaded in ADD mode and

programmed to 9 and 4 respectively, the more

significant unit will have 9 output pulses for every

10 input pulses and the other will have 4 output

pulses for every 100 input pulses for a total of :

9

4

94

 +  = 

10

100

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

9

36

10

10

100

Therefore 36 output pulses for every 100 clock

input pulses

Two HCF4527B Cascaded in the ADD mode with a Preset Number

Inhibit Input Removal Time

5

240

120

ns

10

130

65

15

110

55

Set Removal Time

5

150

75

ns

10

80

40

15

50

25

Clear Removal Time

5

60

30

ns

10

40

20

15

30

15

Symbol

Parameter

Test Condition

Value (*)

Unit

Min.

Typ.

Max.