Pad Description

Pad No.

Pad Name

I/O

Function

1

LOWC

B

For the supply voltage detector, open the pin when not in use.

2

VSS

¾

Negative power supply, GND

3

SC

B

Common point, NMOS open drain

4

RF

O

Connect reference resistor, PMOS open drain

5

RS

O

Connect sensor resistor, PMOS open drain

6

VDD

¾

Positive power supply

7

PSW

I

Pull-low input pin, push switch to turn power on or off

8

TEST2

I

Pull-low test pin, for production test, floating LCD displays the real time value,

when connected to VDD, LCD displays the highest value.

9

CLFH

I

Floating for

°C, connect to VDD for °F

10

OSCI

I

For system oscillator in

11

OSCO

O

For system oscillator out

12

BZ1

O

Buzzer output 1

13

BZ2

O

Buzzer output 2

14~16

COM1~COM3

O

LCD backplane drive, 3-level voltage out

17~19

SA1~SA3

O

LCD segment drive

20~22

SB1~SB3

O

LCD segment drive

23~25

SC1~SC3

O

LCD segment drive

26

SD1

O

LCD segment drive

27

VEE

O

Generate negative voltage (

-1.5V)

28

CAP

O

For negative voltage, NMOS output

29

C512

O

For negative voltage, inverter output

30

TV

B

Test pin for IC

31

TEST1

I

Test pin for IC

32

TIM

I

Test pin for IC

33

TS816

I

Test pin for IC

Absolute Maximum Ratings

Supply voltage...............................................0V to 2.0V

Operation Temperature........................

-2.0°Cto+75°C

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

-55°C to +125°C

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.

HT7500

Rev. 1.10

3

November 27, 2001