HT16562

1/2 Duty VFD Digital Clock

Block Diagram

Note:

²*² col indicates a blink colon and col¢ indicates a continuous light colon.

Rev. 1.20

1

December 17, 2010

Features

operating voltage range

General Description

The HT16562 provides direct drive to VFD panels to im-

plement a 12 hour clock function. Obtaining its time

base from a 4.194304MHz crystal oscillation source

and in having a wide operating voltage due to its internal

voltage regulator, the device also contains a host of

other features. These include a choice of adjustment

modes, including single push increment or 2Hz fast for-

ward functions. Additional features are provided in the

form of Blank control, Zero adjustment and four levels of

illumination control.

V o l t a g e R e g u l a t o r C i r c u i t

G R 1

1 a , 3 a

1 b , 3 b

1 c , 3 c

1 d , 3 d

1 e , 3 e

1 f , 3 f

1 g , 3 g

2 a , 2 d

2 b , 4 b , 4 c

2 c , c o l *

2 c , c o l ' *

2 e

2 f

2 g

C o l o n

F r e q u e n c y

F r e q u e n c y D r i v e r C i r c u i t

O s c i l l a t o r

G R 2

V C C

V D D

6 4 H z

T E S T

B L A N K

D I M 1

D I M 2

X T

X T

V S S

A / C

Z A

H S

M S

G r i d

D e c o d e r

B r i g h t n e s s A d j u s t m e n t

H o u r C o u n t e r

M i n u t e C o u n t e r

S e c o n d C o u n t e r

S e g m e n t

D e c o d e r