7-795

FIGURE 8. CODE CONVERSION CIRCUIT

0123456789

ABCD

CD4028BMS

01234567

0123456789

ABC

D

CD4028BMS

01234567

INPUTS

16 OUTPUTS

1/6 CD4069B

CD4028BMS

FIGURE 7. TYPICAL TRANSITION TIME AS A FUNCTION OF LOAD CAPACITANCE

LOAD CAPACITANCE (CL) (pF)

0

40

60

80

100

20

0

50

100

150

200

SUPPLY VOLTAGE (VDD) = 5V

10V

15V

Typical Applications

The circuit shown in Figure 8 converts any 4-bit code to a

decimal or hexadecimal code. Table 2 shows a number of

codes and the decimal or hexadecimal number in these

codes which must be applied to the input terminals of the

CD4028BMS to select a particular output. For example: in

order to get a high on output number 8 the input must be

either an 8 expressed in 4-bit Binary code, a 15 expressed in

4-Bit Gray code, or a 5 expressed in Excess-3 code.

TABLE 2. CODE CONVERSION CHART

INPUTS

INPUT CODES

OUTPUT NUMBER

HEXA-

DECIMAL

DECIMAL

DCBA

0123456789

10

11

12

13

14

15

0000

0

0

001000000000000000

0001

1

1

110100000000000000

0010

2

3

0

220010000000000000

0011

3203

3

0001000000000000

0100

4714

4

0000100000000000

0101

5

6

2

30000010000000000

0110

6431

40000001000000000

0111

7542

0000000100000000

1000

8

15

5

0000000010000000

1001

9

14

6

50000000001000000

1010

10

12

7

9

60000000000100000