Pad Description

Pad No.

Pad Name

I/O

Internal

Connection

Description

1, 2

VSS

¾¾

Negative power supply, ground

3,

19, 20

COM1

COM3, COM2

O

CMOS

Output for LCD panel common

4~18

SEG1~SEG15

O

CMOS

LCD segment output driver

21

MODE

I

CMOS with

Pull-high

Mode select input pin (Internal pull-high 75K)

22

SEL

I

CMOS with

Pull-high

Correction digit shift switch (Internal pull-high 75K)

23

SET

I

CMOS with

Pull-high

Correction digit data (Internal pull-high 75K)

24

SEGON

I

CMOS with

Pull-high

Est pin, if pull-low will force all segment

²ON²

25

RESET

I

CMOS with

Pull-low

External Reset input (Internal pull-low, 50K)

26

TEST1

I

CMOS with

Pull-low

Test pin (not for customer)

27

OSCO

O

CMOS

Crystal oscillator output pin

28

OSCI

I

CMOS

Crystal oscillator input pin

29, 30

VDD

¾¾

Positive power supply

31

VF4

O

CMOS

Double reference voltage

32, 33

LC2, LC1

I

CMOS

Connected to 0.1

mF capacitor

34

VF2

O

CMOS

Reference voltage

35~40

RF1~RF6

I

¾

Adjust regulator output voltage, TRIM PIN

41~44

TR1~TR4

I

¾

Adjust constant voltage and drive lamp output pin (Open drain)

45

T

I

CMOS with

Pull-high

Imprint time select input (Internal pull-high 75K with

²Latch type²)

46

D

I

CMOS with

Pull-high

Imprint time external control input (Internal pull-high 75K with

²Latch type²)

47

X

I

CMOS with

Pull-high

Imprint trigger input pin (Internal pull-high 75K)*

48

TEST2

I

CMOS with

Pull-high

For coustomer test

²PRINTING LCD² use only, pull-low will force

Lamp

²ON² and other function is OK (Internal pull-high 75K)**

49

LAMP

O

CMOS

Drive lamp output pin (Open drain)

Note:

* The X input has no effect in OFF mode, selection and setting mode; the lamp will be turned off automatically.

** The TEST2 has no effect in selection and setting mode; the lamp will be turned off automatically.

Absolute Maximum Ratings

Supply Voltage .......................................................5.5V

Storage Temperature ............................

-20°Cto60°C

Input Voltage ......................................................... 5.5V

Operating Temperature...............................0

°Cto50°C

Static Electricity (OFF Power)...................................................................................200pF,

±200V, 10 times to each pin

Note: These are stress ratings only. Stresses exceeding the range specified under

²Absolute Maximum 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 exposure to extreme conditions may affect device reliabil-

ity.

HT6750A

Rev. 1.00

3

January 17, 2003