© 2008 Microchip Technology Inc.

DS21394D-page 7

TC14433/A

16

19

Digit select pin. The digit select output goes high when the respective digit is

selected. The MSD (1/2 digit turns on immediately after an EOC pulse).

17

20

The remaining digits turn on in sequence from MSD to LSD.

18

21

To ensure that the BCD data has settled, an inter digit blanking time of two

clock periods is included.

19

23

Clock frequency divided by 80 equals multiplex rate. For example, a system

clock of 60 kHz gives a multiplex rate of 0.8 kHz.

20

24

See Figure 5-4 for digit select timing diagram.

21

25

BCD data output pin. Multiplexed BCD outputs contain three full digits of

22

26

available.

23

27

Refer to the Truth Table 5-1.

24

28

Positive power supply. This is the most positive power supply pin.

—

1

NC

Not Used.

—

8

NC

Not Used.

—

15

NC

Not Used.

—

22

NC

Not Used.

TABLE 3-1:

PIN FUNCTION TABLE (CONTINUED)

Pin No.

24-Pin PDIP,

SOIC

Pin No.

28-Pin

PLCC

Symbol

Description