Pin Description

Pin No.

Pin Name I/O

Description

1

OSC1

I

System clock input

2, 4

VSS

¾ Negative power supply, ground

3

VDD

¾ Positive power supply

5, 6

IO0~IO1

O

Customer defined optional output lines

39, 40,

7~12

C0~C7

I

Keyboard matrix scanning input pins

16~23, 28,

29, 13~15

24, 26, 27

33, 35

R0~R18

O

Keyboard matrix scanning output pins

25, 34

NC

¾ No connection

30

SCRL

O

LED pin

31

NUM

O

LED pin

32

CAP

O

LED pin

37

CLOCK

I/O Synchronous clock signal. Used to clock the transmission data

38

DATA

I/O Bidirectional data transmission line

Absolute Maximum Ratings

Supply Voltage............................4.75V to 5.25V

Storage Temperature.................-55°Cto125°C

Operating Temperature ..................0°Cto70°C

Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maxi-

mum Ratings² may cause substantial damage to the device. Functional operation of this device

at other conditions beyond those listed in the specification is not implied and prolonged expo-

sure to extreme conditions may affect device reliability.

HT82K28A

2

February 16, 2000