HT16565 24 Hour System VFD Digital Clock

HT16565
24 Hour System VFD Digital Clock
Features
· VFD display 24 hour clock function
· Integrated voltage regulator permits wide 4V to 18V
operating voltage range
· 4.194304MHz crystal oscillation
· Four level contrast control function
· Zero adjust function
· 44-pin QFP package
General Description
The HT16565 provides direct drive to VFD panels to implement a 24 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 device also contains a host of other features. These in-
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.
Block Diagram
C M O S
O S C O
F r e q u e n c y D iv id e r s
O s c illa to r
6 4 H z
1 H z
1 H z
O S C I
V
D D
T E S T 3
T e s t
A d ju s tm e n t
T E S T 2
T E S T 1
S e c o n d C o u n te r
a 1
V
V
D D
b 1
D D
c 1
S E
Z A
H S
V
D e c o d e r
S e g m e n t
H o u r C o u n te r
D e c o d e r
S e g m e n t
O p e n D r a in ]
M S
M in u te C o u n te r
D r iv e r [P C H
T im e A d ju s tm e n t
A /C
g 3
b 4
D D
c 4
C O N T 2
a 4 , d 4
C o n tra s t
A d ju s tm e n t
C O N T 1
D IM
V
e 4 , g 4
D D
T E S T 4
V
D D
S 1 2 2 4
Rev. 1.10
1
May 24, 2012
HT16565
Pin Assignment
T
T
T
T
3 0
g 2
5
e 2
c 2
6
7
g 1
e 1
d 1
c 1
2 9
H T 1 6 5 6 5
4 4 Q F P -A
2 8
2 7
8
2 6
9
2 5
1 0
2 4
1 1
2 3
1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2
a 3
T
b 3
T
1 H z
f2
a 2 , d 2
b 2
f1
a 1
b 1
T
T
c 1
d 1
3 1
4
e 4 , g
Z
E S T
E S T
N
E S T
E S T
M
H
a 4 , d
e 1
3
b 4
f3
g 1
3 2
3 3
c 2
e 2
d 3
c 3
2
g 2
1
e 3
c 3
d 3
e 3
4
S
S
2
3
C
4
1
A
4
c 4
g 3
a 4 , d
H
M
E S T
E S T
N
E S T
E S T
Z
e 4 , g
4 4 4 3 4 2 4 1 4 0 3 9 3 8 3 7 3 6 3 5 3 4
g 3
4 4 4 3 4 2 4 1 4 0 3 9 3 8 3 7 3 6 3 5 3 4
c 4
1
A
2
3 2
3
3 1
4
1
4
3 0
4
5
C
H T 1 6 5 6 5 B
4 4 Q F P -B
6
3
7
2
8
S
S
2 9
2 8
2 7
2 6
9
4
3 3
2 5
1 0
2 4
1 1
2 3
1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2
6 4 H
D IM
S E
V D D
C O N
N C
C O N
V S S
O S C
O S C
A /C
z
T 1
T 2
I
O
z
O
I
b 1
a 1
f1
b 2
a 2 , d 2
f2
1 H z
b 3
a 3
f3
b 4
A /C
O S C
O S C
V S S
C O N
N C
C O N
V D D
S E
D IM
6 4 H
T 2
T 1
Pin Description
Pin Name
I/O
Description
VDD
O
High voltage power supply pin.
VSS
¾
Ground pin.
DIM
I
CONT1
I
CONT2
I
Illumination level control pins.
Internally connected to pull-up resistors.
A/C
I
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.
ZA
I
Zero adjustment pin.
Internally connected to a pull-down resistor.
HS
I
Hour adjustment pin.
Internally connected to a pull-down resistor.
MS
I
Minute adjustment pin.
Internally connected to a pull-down resistor.
SE
I
Set enable pin.
Internally connected to a pull-up resistor.
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
O
Segment output pins for VFD
Illumination level control pins.
Internally connected to pull-down resistors.
Crystal oscillator pin
a1, a3 ~ b2, b4, c4
a4, d4, e4, g4
1Hz
Rev. 1.10
2
May 24, 2012
HT16565
Approximate Internal Connections
Z A , M S , H S , D IM , C O N T 1 ,
T E S T 1 , T E S T 2
A /C , S E , C O N T 2 , T E S T 3 , T E S T 4
6 4 H z
V D D
V D D
V D D
V S S
V S S
V S S
a 1 , a 3 ~ g 1 , g 3 ; a 2 , d 2 ~ g 2 ;
a 4 , d 4 , e 4 , g 4
O S C I, O S C O
O S C O
( O s c illa to r O u tp u t)
V D D
O S C I
( O s c illa to r In p u t)
V S S
Absolute Maximum Ratings
Logic Supply Voltage .................VSS-0.3V to VSS+6.5V
Driver Supply Voltage .................VSS-0.3V to VSS+20V
High Input Voltage .....................VSS-0.3V to VCC+0.3V
High Output Voltage ..................VSS-0.3V to VCC+0.3V
Driver Output Voltage..........................VSS-0.3V to VDD
Driver Output Current (Segment Driver) -10mA to +2mA
Driver Output Current (Grid Driver) ......-7mA to +20mA
Storage Temperature ..........................-55°C to +150°C
Operating Temperature.........................-40°C to +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.
Recommended Operating Conditions
Symbol
Parameter
Min.
Typ.
Max.
Unit
VDD
Power Supply Voltage
4
¾
18
V
fOSC
Oscillation Frequency
¾
4.194304
¾
MHz
tOP
Operating Temperature
-40
¾
85
°C
Rev. 1.10
3
May 24, 2012
HT16565
D.C. Characteristics
VDD=6.0V, VSS=0V, Ta=-40°C~85°C
Test Conditions
Symbol
Parameter
VDD
Conditions
Min.
Typ.
Max.
Unit
VIH
High Input Voltage
6V
¾
4.3
¾
¾
V
VIL
Low Input Voltage
6V
¾
¾
¾
1.0
V
IIH
Hi-level Input Current
6V
VI=VDD for TEST1, TEST2,
ZA, MS, HS, DIM, CONT1
30
¾
150
mA
IIL1
VI=Vss for TEST3, TEST4
-120
¾
-800
mA
IIL2
VI=Vss for A/C
-3
¾
-12
mA
VI=Vss for SE, CONT2
-30
¾
-150
mA
Low-level Input Current
6V
IIL3
VOL
Low-level Output current
6V
IOL=VSS for all pin
5.9
¾
¾
V
VOH
Hi-level Output current
6V
IOH=VSS for 64Hz pin
¾
¾
0.1
V
IOH1
Output Current
6V
VOH=4.0V for 1Hz, a2, d2,
a4, d4, e4, g4
¾
¾
-2000
mA
IOL1
Output Current
6V
VOL=0V for 1Hz, a2, d2,
a4, d4, e4, g4
1
¾
¾
mA
IOH2
Output Current
6V
VOH=4.0V, Other segment
output pins except above
¾
¾
-1000
mA
IOL2
Output Current
6V
VOL=VSS, Other segment
output pins except above
1
¾
¾
mA
IOH3
Output Current
6V
VOH=5.5V for 64Hz pin
¾
¾
-100
mA
IOL3
Output Current
6V
VOL=0.5V for 64Hz pin
100
¾
¾
mA
¾
¾
0.8
mA
Dynamic Current Consumption
fOSC=4.194304MHz,
No load, CIN=39pF±5%,
COUT=33pF±5%,
12V
CI=70W±5%
¾
¾
1.6
mA
6V
IDD
Characteristics Curves
VDD vs IDD Characteristics Curve
ID
D
Ta=25°C
ID
(m A )
D
v s V
D D
C h a r a c te r is tic s C u r v e
2 .5
2 .0
1 .5
1 .0
0 .5
0
2
4
6
8
1 0
1 2
1 4
1 6
V
1 8
Rev. 1.10
4
D D
(V )
May 24, 2012
HT16565
Functional Description
VFD Display Driving
Other Pin Functions
The device can directly drive VFD clock panels dynamically. The clock will be displayed in a 24-hour format with
the hours ranging from 0 to 23 and and minutes from 00
to 59. If the most significant numeral is zero then the display will be extinguished.
The external reset pin A/C is used to reset the internal
circuit of the device. When this pin is pulled low the device will be reset, when the pin is allowed to go high, via
its internal pull-high resistor, then the display will indicate a ²0:00² output.
· Segment connections
In the open status, the SE pin is held to ²high² level by a
pull-high resistor, enabling the inputs from MS, HS and
ZA pins. These inputs become invalid by setting this pin
to a ²low² level externally.
A 7-segment display is shown below showing the illumination pattern for each numeral.
A
F
B
G
E
D
C
7 -S e g m e n ts
The 64Hz pin allows monitoring of the system frequency
to allow frequency adjustments to be executed. As the
name suggests, this output pin will continuously output
a frequency of 64Hz.
In the open status, the TEST1 and TEST2 pins are kept
at a ²0² level by pull-down resistors.
As the device is designed for clock applications, four
7-segment displays are required to display the correct
time output. The connections for the segments are
shown below, however it should be noted that the
fourth segment only requires two of its segments to be
driven.
a 4
a 3
g 4
e 4
d 4
f3
b 4
c 4
d ig it4
e 3
f2
b 3
g 3
c 3
d 3
e 2
1 H z
d ig it3
f1
b 2
g 2
d 2
The Test pin function is as shown in the following table.
a 1
a 2
1 H z
In the open status, the TEST3 and TEST4 pins are kept
at a ²1² level by pull-up resistors.
c 2
d ig it2
e 1
b 1
g 1
d 1
c 1
d ig it1
TEST select function 1
Switch Pin Name
Operating mode
TEST1
TEST2
TEST3
0
(or Open)
0
(or Open)
1
(or Open)
Normal function.
F(Pulse)
1
1
(or Open)
Input pulses to the 16.384kHz system of the circuit.
1
F(Pulse)
1
(or Open)
Input pulses to the 16.384kHz system of the circuit.
1
F(Pulse)
0
Input pulses to the 64Hz system of the circuit.
F(Pulse)
1
0
Input pulses to the 64Hz system of the circuit.
F(Pulse)
0
(or Open)
0
Input pulses for the minute and hour counters, which advances 1 count
with 1 pulse. No carry functions for hour and minute counters.
TEST select function 2
Switch Pin Name
Operating mode
TEST3
DIM
CONT1
CONT2
0
F(Pulse)
*
*
The pulse widths of the all segment outputs are controlled
by the pulse width of the DIM signal
0
0
*
*
Sets all segment outputs to high impedance
Note: ²*² Indicates that the input level can be ²0² and ²1²
Rev. 1.10
5
May 24, 2012
HT16565
Three illumination level set pins, DIM, CONT1 and CONT2 are provided to give control over the display brightness
level, as shown in the following table.
Switch Pin Name
Operating mode
DIM
CONT1
CONT2
0
(or Open)
*
*
1
0
(or Open)
1
(or Open)
1
0
(or Open)
0
12.5% (1/8) duty display at 4096Hz
1
1
1
(or Open)
6.25% (1/16) duty display at 4096Hz
100% duty display
25% (1/4) duty display at 4096Hz
Note: ²1² high level, ²0² low level, ²*² don¢t care
· Zero adjustment
Device Functions
A zero adjust function is also included within the device and is controlled by the ZA pin. This pin is connected to an internal pull low resistor. Pulling this line
high will reset both the internal minutes and seconds
value, however the way in which the display is reset
depends upon the present value of display. If the minute value is presently less than 30 the only the second
and minute values will be reset to zero and the hour
value remain unchanged. However if the minute value
is presently at a value of 30 or higher then when the
zero adjustment function is executed, a carry will be
implemented and the hour value will be increment by
one. The following table illustrates a few examples of
this operation.
· Reset
Although the device is provided with an external reset
pin A/C, the device will in fact reset itself when power
is applied, eliminating the need for external reset components. The usual provision of an external capacitor
is not required as an internal reset capacitor is integrated within the device.
· Chatter removal
The device contains circuits which are connected to
input pins HS, MS and ZA to remove chatter of less
than 31.25ms.
· Oscillator
The basic time base frequency for this device is determined by an external 4.194304MHz crystal. When an
external crystal along with two small external capacitors are connected to the two oscillator pins, the internal oscillator circuit will ensure generation of the
correct time base signals. The oscillation frequency,
although determined by the external crystal frequency, will also be influenced by the external capacitors, the crystal inherent capacitance and the residual
capacitance of the external PCB tracks. To ensure accurate frequency generation, the crystal specification
should be taken into account and care taken to place
the external capacitors and crystal as close to the device as possible.
Zero Adjust Examples
Present Time
After Zero Adjust
Hr.
Min.
Sec.
Hr.
Min.
Sec.
1
30
00
2
00
00
2
00
00
2
00
00
2
29
59
2
00
00
2
30
00
3
00
00
2
59
59
3
00
00
3
29
59
3
00
00
Time Adjustment Operation
· Hour/minute adjustment
Both the minutes and hour displays can be adjusted
separately or both together in a fast forward format.
The hour set pin, HS, and the minutes set pin, MS, are
used to make these adjustments. Both of these pins
are connected to internal pull-low resistors. Each time
one of these lines is pulled high, the respective hour or
minute value will increment by one, also if the line is
continuously held high then the respective value will
increment automatically at a rate of 2Hz. Both values
will increment together if both lines are pulled high simultaneously. Note that no carry functions will be implemented when either the hour or minute value
overflows.
Rev. 1.10
6
May 24, 2012
HT16565
Application Circuits
V
V
E f
C C
D D
F +
V D D
T E S T 1
T E S T 1
1 H z
a 1
b 1
c 1
d 1
e 1
f1
g 1
a 2 , d 2
b 2
c 2
e 2
f2
g 2
a 3
b 3
c 3
d 3
e 3
f3
g 3
b 4
c 4
a 4 , d 4
e 4 , g 4
T E S T 2
T E S T 2
H S
H S
M S
M S
Z A
Z A
D IM
D IM
C O N T 1
C O N T 1
T E S T 3
T E S T 3
T E S T 4
T E S T 4
S E
1 H z
a 1
b 1
c 1
d 1
e 1
f1
g 1
a 2 ,
b 2
c 2
e 2
f2
g 2
a 3
b 3
c 3
d 3
e 3
f3
g 3
b 4
c 4
a 4 ,
e 4 ,
F -
d 2
S ta tic T y p e
C lo c k V F D
d 4
g 4
S E
A /C
O S C O
A /C
C 1
Y 1
4 .1 9 4 3 0 4 M H z
C O N T 2
C O N T 2
O S C I
C 2
1
6 4 H z
V S S
J 1
C O N 1
Note: Capacitors C1 and C2 can adjust the frequency accuracy
Rev. 1.10
7
May 24, 2012
HT16565
Package Information
Note that the package information provided here is for consultation purposes only. As this information may be updated at regular intervals users are reminded to consult the Holtek website (http://www.holtek.com.tw/english/literature/package.pdf) for
the latest version of the package information.
44-pin QFP (10mm´10mm) Outline Dimensions
H
C
D
3 3
G
2 3
I
3 4
2 2
L
F
A
B
E
1 2
4 4
K
=
J
1
Symbol
Dimensions in inch
Min.
Nom.
Max.
A
0.512
¾
0.528
B
0.390
¾
0.398
C
0.512
¾
0.528
D
0.390
¾
0.398
E
¾
0.031
¾
F
¾
0.012
¾
G
0.075
¾
0.087
H
¾
¾
0.106
I
0.010
¾
0.020
J
0.029
¾
0.037
K
0.004
¾
0.008
L
¾
0.004
¾
a
0°
¾
7°
Symbol
Rev. 1.10
1 1
Dimensions in mm
Min.
Nom.
Max.
A
13.00
¾
13.40
B
9.90
¾
10.10
C
13.00
¾
13.40
D
9.90
¾
10.10
E
¾
0.80
¾
F
¾
0.30
¾
G
1.90
¾
2.20
H
¾
¾
2.70
I
0.25
¾
0.50
J
0.73
¾
0.93
K
0.10
¾
0.20
L
¾
0.10
¾
a
0°
¾
7°
8
May 24, 2012
HT16565
Holtek Semiconductor Inc. (Headquarters)
No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan
Tel: 886-3-563-1999
Fax: 886-3-563-1189
http://www.holtek.com.tw
Holtek Semiconductor Inc. (Taipei Sales Office)
4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, Taiwan
Tel: 886-2-2655-7070
Fax: 886-2-2655-7373
Fax: 886-2-2655-7383 (International sales hotline)
Holtek Semiconductor Inc. (Shenzhen Sales Office)
5F, Unit A, Productivity Building, No.5 Gaoxin M 2nd Road, Nanshan District, Shenzhen, China 518057
Tel: 86-755-8616-9908, 86-755-8616-9308
Fax: 86-755-8616-9722
Holtek Semiconductor (USA), Inc. (North America Sales Office)
46729 Fremont Blvd., Fremont, CA 94538
Tel: 1-510-252-9880
Fax: 1-510-252-9885
http://www.holtek.com
Copyright Ó 2012 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used
solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable
without further modification, nor recommends the use of its products for application that may present a risk to human life
due to malfunction or otherwise. Holtek¢s products are not authorized for use as critical components in life support devices
or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information,
please visit our web site at http://www.holtek.com.tw.
Rev. 1.10
9
May 24, 2012