Holtek Semiconductor Inc HT16561 Datasheet
Features
·
VFD display 12 hour clock function
·
4.194304MHz crystal oscillation
·
Zero adjust function
General Description
The HT16561 provides direct drive to VFD panels to im
plement a 12 hour clock function. In addition to obtaining
its time base from a 4.194304MHz crystal oscillation
source and in having a wide operating voltage, the de
vice also contains a host of other features. These in
Block Diagram
HT16561
VFD Digital Clock
·
Integrated voltageregulator permitswide 4Vto 16V
operating voltage range
·
Four level contrast control function
·
44-pin QFP package
clude a choice of adjustment modes, including single
push increment or 2Hz fast forward functions. Additional
features are provided in the form of Zero adjustment and
four levels of contrast control.
-
-
O S C O
O S C I
T E S T 3
T E S T 2
T E S T 1
A / C
C O N T 2
C O N T 1
D I M
C M O S
O s c i l l a t o r
V
D D
T e s t
A d j u s t m e n t
V
D D
V
D D
S E
Z A
M S
H S
V
D D
C o n t r a s t
A d j u s t m e n t
F r e q u e n c y D i v i d e r s
T i m e A d j u s t m e n t
1 H z
S e c o n d C o u n t e r
( 1 / 6 0 )
M i n u t e C o u n t e r
( 1 / 6 0 )
H o u r C o u n t e r
( 1 / 1 2 )
A M / P M
D e c o d e r
S e g m e n t
D r i v e r [ P C H O p e n D r a i n ]
D e c o d e r
S e g m e n t
6 4 H z
1 H z
a 1
b 1
c 1
g 3
b 4
c 4
A M
P M
V
D D
T E S T 4
Rev. 1.00 1 February 7, 2007
HT16561
Pin Assignment
T E S T 4
T E S T 1
P M
Z A
c 4
g 3
1
2
e 3
d 3
3
c 3
4
5
g 2
e 2
6
7
c 2
g 1
8
e 1
9
d 1
1 0
c 1
1 1
1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2
V D D
S E
D I M
6 4 H z
N C
H T 1 6 5 6 1
4 4 Q F P - A
N C
C O N T 1
T E S T 2
T E S T 3
M S
A M
H S
3 43 53 63 73 83 94 04 14 24 34 4
b 4
3 3
3 2
f 3
a 3
3 1
b 3
3 0
1 H z
2 9
f 2
2 8
a 2 , d 2
2 7
b 2
2 6
f 1
2 5
a 1
2 4
b 1
2 3
C O N T 2
A / C
O S C O
O S C I
V S S
c 4
P M
Z A
T E S T 1
T E S T 4
N C
T E S T 3
T E S T 2
M S
H S
A M
d 3
e 3
g 3
c 3
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
b 3
a 3
f 3
b 4
Pin Description
Pin Name I/O Description
VDD O High voltage power supply pin.
VSS
DIM I
CONT1 I
CONT2 I
A/C I
ZA I
HS I
MS I
SE I
OSCO O
OSCI I
TEST1, TEST2 I IC test pin - should be left open or kept at a low level
TEST3, TEST4 I IC test pin - should be left open or kept at a high level
64Hz O 64Hz signal output pin for oscillation frequency adjustment
a1, a3 ~ b2, b4, c4
1Hz
Ground pin.
¾
Illumination level control pins.
Internally connected to pull-down resistors.
Illumination level control pins.
Internally connected to pull-up resistors.
When the A/C pin is low, the internal circuits are reset.
The reset pulse width should be more than 2ms.
Internally connected to a pull-up resistor.
Zero adjustment pin.
Internally connected to a pull-down resistor.
Hour adjustment pin.
Internally connected to a pull-down resistor.
Minute adjustment pin.
Internally connected to a pull-down resistor.
Set enable pin.
Internally connected to a pull-up resistor.
Crystal oscillator pin
O Segment output pins for VFDAM, PM
e 2
g 2
H T 1 6 5 6 1 B
4 4 Q F P - B
f 2
1 H z
d 1
e 1
g 1
c 2
a 2 , d 2
c 1
3 43 53 63 73 83 94 04 14 24 34 4
6 4 H z
3 3
3 2
D I M
S E
3 1
V D D
3 0
C O N T 1
2 9
N C
2 8
C O N T 2
2 7
V S S
2 6
O S C I
2 5
O S C O
2 4
A / C
2 3
b 1
a 1
f 1
b 2
Rev. 1.00 2 February 7, 2007
Approximate Internal Connections
HT16561
Z A , M S , H S , D I M , C O N T 1 ,
T E S T 1 , T E S T 2
a 1 , a 3 ~ g 1 , g 3 ; a 2 , d 2 ~ g 2 ;
A M , P M
V D D
V S S
V D D
A / C , S E , C O N T 2 , T E S T 3 , T E S T 4
V D D
V S S
O S C I , O S C O
O S C O
( O s c i l l a t o r O u t p u t )
O S C I
( O s c i l l a t o r I n p u t )
V S S
6 4 H z
V D D
V S S
Absolute Maximum Ratings
Logic Supply Voltage .................VSS-0.3V to VSS+6.5V
High Input Voltage .....................V
Driver Output Voltage..........................V
-0.3V to VCC+0.3V
SS
-0.3V to V
SS
DD
Driver Output Current (Grid Driver) ......-7mA to +20mA
Driver Supply Voltage .................V
High Output Voltage ..................V
Driver Output Current (Segment Driver) -10mA to +2mA
Storage Temperature..........................-55°C to +150°C
Operating Temperature.........................-40°Cto+85°C
Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maximum Ratings² may
cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed
in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.
-0.3V to VSS+20V
SS
-0.3V to VCC+0.3V
SS
Recommended Operating Conditions
Symbol Parameter Min. Typ. Max. Unit
V
f
OSC
t
OP
DD
Power Supply Voltage 4
Oscillation Frequency
Operating Temperature
-40 ¾
¾
¾
4.194304
16 V
¾
MHz
85
°C
Rev. 1.00 3 February 7, 2007
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