5-1
KEY BOARD
TABLE OF CONTENTS
IC Block Diagram ........................................................................ 5-1
Circuit Diagram ........................................................................... 5-2
Layout Diagram-Component ...................................................... 5-3
Layout Diagram-SMD ................................................................. 5-3
Electrical parts list ...................................................................... 5-4
5-1
Block Diagram
Pin Assignment
HT1622
2 January 10, 2001
S E G 1 2
N C
S E G 8
S E G 9
S E G 1 0
S E G 1 1
N C
S E G 1 9
S E G 1 8
S E G 1 7
S E G 1 6
S E G 1 5
S E G 1 4
S E G 1 3
N C
N C
N C
N C
S E G 7
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
0 6 $
$ " 3 . 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
N C
S E G 2 0
S E G 2 1
S E G 2 2
C S
B Z
N C
R D
W R
D A T A
V S S
O S C I
V D D
V L C D
I R Q
N C
B Z
T 1
T 2
C O M 1
N C
T 3
C O M 0
C O M 5
C O M 2
C O M 3
C O M 4
C O M 6
C O M 7
S E G 0
S E G 1
S E G 2
S E G 3
S E G 4
S E G 5
S E G 6
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
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 I
C S
R D
C O M 0
C O M 7
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