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

Pin Assignment

HT1621

Rev. 2.60

2

October 28, 2009

PATENTED

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

a n d

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

V L C D

S E G 7

S E G 6

S E G 5

S E G 4

S E G 3

S E G 2

S E G 1

S E G 0

C S

R D

W R

D A T A

V S S

O S C O

O S C I

V L C D

V D D

I R Q

B Z

B Z

C O M 0

C O M 1

C O M 2

C O M 3

S E G 8

S E G 9

S E G 1 0

S E G 1 1

S E G 1 2

S E G 1 3

S E G 1 4

S E G 1 5

S E G 1 6

S E G 1 7

S E G 1 8

S E G 1 9

S E G 2 0

S E G 2 1

S E G 2 2

S E G 2 3

S E G 2 4

S E G 2 5

S E G 2 6

S E G 2 7

S E G 2 8

S E G 2 9

S E G 3 0

S E G 3 1

H T 1 6 2 1 B

4 8 S S O P - A

4 8

4 7

4 6

4 5

4 4

4 3

4 2

4 1

4 0

3 9

3 8

3 7

3 6

3 5

3 4

3 3

3 2

3 1

3 0

2 9

2 8

2 7

2 6

2 5

1

2

3

4

5

6

7

8

9

1 0

1 1

1 2

1 3

1 4

1 5

1 6

1 7

1 8

1 9

2 0

2 1

2 2

2 3

2 4

S E G 5

S E G 3

S E G 1

C S

R D

W R

D A T A

V S S

V L C D

V D D

I R Q

B Z

C O M 0

C O M 1

H T 1 6 2 1 D

2 8 S K D I P - A

S E G 7

S E G 9

S E G 1 1

S E G 1 3

S E G 1 5

S E G 1 7

S E G 1 9

S E G 2 1

S E G 2 3

S E G 2 5

S E G 2 7

S E G 2 9

S E G 3 1

C O M 2

2 8

2 7

2 6

2 5

2 4

2 3

2 2

2 1

2 0

1 9

1 8

1 7

1 6

1 5

1

2

3

4

5

6

7

8

9

1 0

1 1

1 2

1 3

1 4

C S

R D

W R

D A T A

V S S

O S C O

O S C I

V L C D

V D D

I R Q

B Z

B Z

S E G 1 2

S E G 1 3

S E G 1 4

S E G 1 5

S E G 1 6

S E G 1 7

S E G 1 8

S G E 1 9

S E G 2 0

S E G 2 1

S E G 2 2

S E G 2 3

2 1 2 2 2 3 2 4

2 5

2 6

2 7

2 8

2 9

3 0

3 1

3 2

3 3

3 4

3 5

3 6

3 7

3 8

3 9

4 0

1

2

3

4

5

6

7

8

9

1 0

1 1

1 2

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

4 8

4 1

4 2

4 3

4 4

4 5

4 6

4 7

H T 1 6 2 1 B

4 8 L Q F P - A

1

2

3

4

5

6

7

8

9

1 0

1 1

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

2 3

2 4

2 5

2 6

2 7

2 8

2 9

3 0

3 1

3 2

3 3

3 4

3 5

3 6

3 7

3 8

3 9

4 0

4 1

4 2

4 3

4 4

H T 1 6 2 1

4 4 Q F P - B

C S

R D

W R

D A T A

V S S

V L C D

V D D

B Z

C O M 0

C O M 1

C O M 2

S E G 1 1

S E G 1 2

S E G 1 3

S E G 1 4

S E G 1 5

S E G 1 6

S E G 1 7

S E G 1 8

S G E 1 9

S E G 2 0

S E G 2 1

N o t e : * P l e a s e n o t e t h a t i n t h e 4 8 - p i n L Q F P p a c k a g e ,

t h e S E G 2 7 a n d S E G 2 8 p i n s a r e n o t i n s e q u e n t i a l o r d e r .