HT16566_12 Datasheet, PDF (1/8 Pages) Holtek Semiconductor Inc – 1/2 Duty VFD Digital Clock

HT16566
1/2 Duty VFD Digital Clock
Features
· VFD display 24 hour clock function
· Directly drive VFD panels at 1/2 Duty cycle
· 4.194304MHz crystal oscillation
· Zero adjust function
· Integrated voltage regulator permits wide 4V to 18V
operating voltage range
· Four levels of illumination control function
· 30-pin SSOP package
General Description
The HT16566 provides direct drive to VFD panels to im-
plement a 24 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.
Block Diagram
VCC
VSS
V DD
V DD
V o lta g e R e g u la to r C ir c u it
VDD
V DD
A /C
ZA
HS
MS
B LA N K
TEST
XT
XT
D IM 1
D IM 2
H o u r C o u n te r
V DD
M in u te C o u n te r
S egm ent
D ecoder
V DD
V DD
S e c o n d C o u n te r
C o lo n
F re q u e n c y
O s c illa to r
F r e q u e n c y D r iv e r C ir c u it
B r ig h tn e s s A d ju s tm e n t
G r id
D ecoder
1a,3a
1b,3b
1c,3c
1d,3d
1e,3e
1 f, 3 f
1g,3g
2a,2d,4a
2b,4b
2 c , c o l*
2 c , c o l'*
2e,4e
2 f, 4 c
2g,4g,4d
64H z
GR1
GR2
Note: ²*² col indicates a blink colon and col¢ indicates a continuous light colon.
Rev. 1.20
1
May 24, 2012