Block Diagram

Note:

CS: Chip selection

BZ, BZ: Tone outputs

WR,RD, DATA: Serial interface

COM0~COM3, SEG0~SEG31: LCD outputs

IRQ: Time base or WDT overflow output

VO15N: Half voltage circuit output pin

VEE: Double voltage circuit output pin

CC1/CC2: External capacitor pin, for double voltage and half voltage circuit use

Pin Assignment

HT1620

Rev. 1.30

2

March 27, 2007

W a t c h d o g T i m e r &

T i m e B a s e G e n e r a t o r

D i s p l a y R A M

L C D D r i v e r /

B i a s C i r c u i t

C o n t r o l

a n d

T i m i n g

C i r c u i t

D A T A

W R

O S C O

O S C I

C S

R D

C O M 0

C O M 3

S E G 0

S E G 3 1

T o n e F r e q u e n c y

G e n e r a t o r

B Z

B Z

I R Q

V S S

V D D

C C 2

C C 1

V O 1 5 N

V E E

5 6

5 7

5 8

5 9

6 0

6 1

6 2

6 3

6 4

5 2

5 3

5 4

5 5

2 3

2 0 2 1 2 2

2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2

4 1

5 1

3 7

3 8

3 9

4 0

4 9

4 8

4 7

4 6

4 5

4 4

4 3

4 2

5 0

3 3

3 4

3 5

3 6

N C

S E G 2 7

N C

N C

N C

N C

N C

S E G 3 1

S E G 3 0

S E G 2 9

S E G 2 8

S E G 2 6

S E G 2 5

S E G 2 4

S E G 2 3

S E G 2 0

N C

S E G 2 2

S E G 2 1

N C

S E G 1

N C

C C 2

V O 1 5 N

V E E

C O M 0

C O M 1

C O M 2

C O M 3

S E G 0

S E G 2

S E G 3

S E G 4

S E G 5

S E G 8

N C

S E G 6

S E G 7

1

1 1

2

3

4

5

6

7

8

9

1 0

1 2

1 3

1 4

1 5

1 8

1 9

1 6

1 7

H T 1 6 2 0

6 4 Q F P - A