®
®
www.datel.com
DSD-40BCD Series
Miniature
4½ Digit, BCD Input
Slave LED Display
Features
•
Low cost! Complete!
No external components required
•
Rugged, epoxy-encapsulated package
•
Ideal for computer-based instruments
•
Miniature size:
2.17" x 0.92" x 0.56"
55mm x 23mm x 14mm
•
Built-in color filter and bezel
•
Single +5V supply, TTL compatible
•
Low-power model, 35mA (175mW)
•
Large (0.52"/13.2mm), matched-
intensity, LED display
•
Choice of red or green LED's
•
Minus sign and decimal points included
•
PC-board or panel mountable
DATEL's new DSD-40BCD digital slave display combines a full-size, 4½ digit,
LED display with all the other necessary components (including a built-in, contrast-
enhancing filter/bezel) to implement a pc-board mountable instrument display. The
epoxy-encapsulated, 24-pin package, measuring only 2.17 x 0.92 x 0.56 inches, is
perfectly sized to occupy the absolute minimum pc-board space. The one-piece LED
display eliminates the need to purchase multiple, matched-intensity LED's — usually
an expensive and limited-availability situation.
The DSD-40BCD's flexible design gives the user full control of all major display
functions including display update rate, number of digits enabled, and decimal point
selection. Its TTL-compatible inputs interface directly with most BCD output, integrat-
ing analog-to-digital converters — no additional glue logic is required! When used
with sophisticated microcomputers, the brightness of any digit can be independently
controlled by simply lowering the digit-drive input duty cycle.
The extremely rugged package allows all models to operate over the temperature
range of 0 to +70°C (at 0 to 95% relative humidity). For power-sensitive designs, the
low-power DSD-40BCD-RL model, with all digits turned on, draws only 35mA from its
+5V supply. This ultra-low power consumption means that even battery-powered
applications can now benefit from the superior readability offered by LED displays.
1
+5V SUPPLY
DIGIT A
DRIVE 5
L
B4
12
N.C.
2
DISPLAY TEST
DIGIT B
DRIVE 1
DIGIT C
DRIVE 2
+5V
K
B2
11
N.C.
3
5V RETURN
J
B1
10
5V RETURN
4
DP 3
DIGIT D
DRIVE 3
POL
DIG 1
DIG 2
DIG 3
DIG 4
DIG 5
I
B8
9
N.C.
5
DP 2
DIGIT E
DRIVE 4
H
N.C.
DP
DP1
DP2
DP3
DP4
8
DP 4
6
DP 1
Segment
Identification
A
F
E
D
G
B
C
F
POLARITY
A
B
C
D
E
F
G
G
N.C.
7
N.C.
DIGIT
DRIVE 1
DIGIT
DRIVE 4
SEVEN-SEGMENT DRIVERS
BCD DECODER
DISPLAY TEST
DP 1
DP 4
Figure 1. DSD-40BCD Series Simplified Schematic
DATEL, Inc., Mansfield, MA 02048 (USA)
•
Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356
•
Email: sales@datel.com
•
Internet: www.datel.com
DSD-40BCD
Functional Specifications
T
A
= +25°C and supply voltage = +5V, unless otherwise noted.
Control Inputs
BCD
(pins I-L)
and TEST
(pin 2)
Inputs:
Low-Level Input Voltage (V
IL
)
Low-Level Input Current (I
IL
)
High-Level Input Voltage (V
IH
)
High-Level Input Current (I
IH
)
Polarity Input
(pin F):
Low-Level Input Voltage (V
IL
)
Low-Level Input Current (I
IL
)
High-Level Input Voltage (V
IH
)
High-Level Input Current (I
IH
)
Digit Drive Inputs
(pins A-E):
Low-Level Input Voltage (V
IL
)
Low-Level Input Current (I
IL
)
High-Level Input Voltage (V
IH
)
High-Level Input Current (I
IH
)
DP1-DP4 Inputs
(pins 4-6, 8):
Low-Level Input Voltage (V
IL
)
Low-Level Input Current (I
IL
)
High-Level Input Voltage (V
IH
)
High-Level Input Current (I
IH
)
Power Supply Requirements
Supply Voltage
Supply Current:
DSD-40BCD-GS
DSD-40BCD-RL
DSD-40BCD-RS
Display
Display Type and Size
LED Peak Wavelength (λ):
λ
DSD-40BCD-GS
DSD-40BCD-RL
DSD-40BCD-RS
Physical/Environmental
Operating Temperature
Storage Temperature
Humidity
(Non-condensing)
Case Material
Weight
BCD Inputs and Resultant Displays
0
–40
0
--
--
--
--
--
--
+4.75
--
--
--
+5.00
+100
+35
+85
Min.
--
--
+2.4
--
--
--
+4.5
--
--
--
+4.5
--
--
--
+4.5
--
Typ.
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
4½ D I G I T, S L A V E L E D D I S P L AY
Technical Notes
Max.
+0.8
0.4
--
0.05
+0.8
0.4
--
0.05
+0.8
0.4
--
2
+0.8
20
--
0.05
+5.25
+130
+45
+110
Units
Volts
mA
Volts
mA
Volts
mA
Volts
mA
Volts
mA
Volts
mA
Volts
mA
Volts
mA
Volts
mA
mA
mA
1. DSD-40BCD Operation
(Please Refer to the Timing and Pinout
Diagrams for the Following Discussion): The DSD-40BCD display has
five digits, labeled digit 1 (left-most digit or MSD) through digit 5 (right-
most digit or LSD), which are turned on by bringing their respective
DIGIT DRIVE inputs to a high logic level. The binary coded decimal
data (BCD) on pins I- L is decoded into the corresponding seven-
segment LED outputs necessary to display the numerals
"0" through "9".
Since there are effectively five digits and only one set of BCD data
inputs, the DSD-40BCD's digits have their segments tied ("multi-
plexed") together. The top segment, referred to as segment A, of digit
5 is connected to the A segment of the other three digits (digit 1 has
no A segment). The remaining B, C, D, E, F and G segments are
connected to each other in the same fashion.
As an example of how the multiplexing scheme works, assume that
the BCD data inputs are 0001 (the BCD code for the decimal number
1) and also assume that the DIGIT DRIVE 3 input is high. Under these
conditions, the B and C segments of digits 1-5 will all be enabled.
However, only the digits whose DIGIT DRIVE inputs are high, in this
case only digit 3, will display the numeral "1". All the other digits will be
off. This example, while technically valid, will produce an extremely
bright "1" for digit 3. This will be explained in greater detail in the
section titled "Controlling the Display Brightness."
2. DSD-40BCD Timing Diagram
(See Figure 2): The timing diagram
depicts the required typical input conditions and timing relationships
that allow the user to access all 5 digits. The recommended display
scan rate is 100Hz. All 5 digits are scanned in 10ms, and each
individual digit is "on" for 2ms (20% duty cycle). The 100Hz figure is
not critical; it can go as low as 70Hz without any impact on
display visibility.
The timing diagram shows the digits being scanned from left to right
(DIGIT 1 to DIGIT 5), but this order is not mandatory. Any drive
sequence can be used, as long as BCD data is presented at the
correct corresponding DIGIT DRIVE interval.
An important point to
keep in mind is that the DSD-40BCD has no internal data latches!
The DIGIT DRIVE and BCD data inputs must be continuously strobed
to keep the display properly illuminated.
3. Decimal Point Inputs (DP1- DP4, Pins 4-6, 8):
The four, active-low,
decimal point segments are multiplexed in a similar, though not
identical, manner as the rest of the digit segments. The four decimal
points are controlled by their respective DIGIT DRIVE inputs. A
selected decimal point may be permanently connected to ground. It
will only be illuminated when its respective DIGIT DRIVE input is high.
For example, if pin 6 (DP1) is hard-wired to pin 3 (5V RETURN), DP1
will only be on during the time interval that DIGIT DRIVE 1 is high.
As the specifications table clearly states, DP1- DP4 each require
20mA of sink current in order to achieve good illumination levels.
Unused decimal points may be left open. The specified minimum
V
IH
applies only if logic-level devices are used to select the
decimal points.
4. POLARITY (Pin F):
The function of this active-low pin is to turn on
the minus sign if negative readings are desired. The polarity input, like
the decimal points, can also be permanently connected to ground.
However, POLARITY is logic-level compatible and does not require
4½ Digit LED, 0.52"/13.2mm high
565
660
635
--
--
--
+70
+75
95
nm
nm
nm
°C
°C
%
Polycarbonate
1 ounce (28 grams)
0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111
Order on-line at www.datel.com
Ordering Information
DSD-40BCD - R S
LED Color: GS
= Standard Green
RL
= Low-Power Red
RS
= Standard Red
Panel cutout punch
DSD-40 bezel assembly
DSD-40 bezel assembly with sealing gasket
Accessories:
DMS-30-CP
DMS-BZL1
DMS-BZL2
A panel-mount retaining clip is supplied with each model.
2
4½ D I G I T, S L A V E L E D D I S P L A Y
DSD-40BCD
the high sink currents that DP1- DP4 do. If negative readings are
never displayed, the POLARITY input may be left open.
5. Controlling Display Brightness:
The LED current-setting
components inside the DSD-40BCD are selected to produce
good display brightness — while keeping power dissipation at
reasonable levels — with a 20% duty cycle. Since no data latches
are utilized in the DSD-40BCD design, the user can exercise full
control over how many digits are enabled, and their relative
brightness, by manipulating the duty cycle of the DIGIT DRIVE
input.
To turn off one digit, for a four digit application, simply leave the
respective DIGIT DRIVE input (DIGIT DRIVE 5 in this example)
open or low. If the timing relationships remain unchanged (i.e.,
20% duty cycle), the display brightness will remain the same as
when all five digits are used. However, if the duty cycle is changed
to 25% (because only four digits are used), the increase in display
intensity will be noticeable. In most applications, this increase in
intensity will not be significant enough to justify any timing
changes.
6. Highlighting Selected Digits:
In many instrument designs, it is
sometimes desirable to highlight or "flash" one particular digit to
draw the user's attention to that digit. Once again, duty cycle
control of the digit drive inputs makes this a relatively simple task.
The easiest way is to flash the digit on and off, at a 0.5 to 1Hz
rate, with the DIGIT DRIVE input. Keeping the duty cycle fixed at
20% for 5-digit applications, and 25% for 4-digits, will keep the
intensity of the non-flashed digits uniform.
7. Power Supply Decoupling:
The DSD-40BCD is not sensitive to
logic noise or spikes, on either the 5V supply or the data inputs,
because it does not use any edge-triggered logic. However, it
does generate a fair amount of switching transients due to the
display's multiplexed architecture. A tantalum electrolytic
capacitor, in the range of 15 to 22µF, in parallel with a 0.1µF
ceramic capacitor will reduce the LED switching transients.
These two capacitors should be located as close as possible to
pins 1 and 3.
8. Interfacing BCD-Output A/D Converters:
The DSD-40BCD
accepts the BCD data from DATEL's DMS-40PC-X-RS-BCD
Series, 4½ Digit Panel Meters. DMS-40PC meters are exactly the
same size as the DSD-40BCD display making it ideal for use in
remote-display applications.
The DSD-40BCD will also interface directly with the ICL7135,
4½ digit, integrating A/D converter's BCD and DIGIT DRIVE
outputs. The only difference is that the ICL7135 has its five DIGIT
DRIVE outputs labeled in a right-to-left order, i.e., the 7135's
MSD is labeled digit 5 and its LSD is labeled digit 1. This is
opposite to the DSD-40BCD labeling its MSD digit 1 and its
LSD digit 5. Please refer to the 7135's data sheet for more
information.
9. DISPLAY TEST (Pin 2):
The DSD-40BCD's display can have all
its segments enabled by bringing DISPLAY TEST low. The
display will show "–18888" (excluding the decimal points) as long
as the digit drive inputs are continuously strobed.
10. Soldering Methods:
DSD-40BCD Series displays easily
withstand most common manual and wave soldering operations.
However, we highly recommend that you evaluate the effects your
particular soldering techniques may have on the display's
polycarbonate case and overall performance. We also recom-
mend the use of no-clean solders since their residue normally
has no detrimental effects on low-speed digital devices.
11. Suggested Mating Connectors:
Board mounted:
Socket
DATEL P/N 39-2359624
Panel mounted:
DATEL recommends the use of IDC (insulation displacement)
connectors when panel mounting the DSD-40BCD. SAMTEC's
HCS series of IDC cable strips can be ordered in a variety of
lengths and connector terminations. Please contact SAMTEC,
Inc. at:
USA
(Indiana)
Europe
(Scotland)
Asia
(Singapore)
812-944-6733
01236-739292
65-745-5955
Fax: 812-948-5047
Fax: 01236-727113
Fax: 65-841-1502
Approx. 8msec
Approx. 2msec
Approx. 2msec
DIGIT DRIVE 1
(MSD)
DIGIT DRIVE 2
DIGIT DRIVE 3
DIGIT DRIVE 4
DIGIT DRIVE 5
(LSD)
BCD DATA
(4 LINES)
1
MSD
2
3
4
5
LSD
1
2
3
4
5
Notes:
1. Maximum allowable digit-to-digit overlap is 5 sec.
2. Maximum allowable digit-to-BCD data skew is also 5 sec.
Figure 2. BCD Data Timing Diagram
3
DSD-40BCD
4½ D I G I T, S L A V E L E D D I S P L A Y
Mechanical Specifications
MADE IN USA
LEAD DIMENSIONS: 0.025 (0.635) x 0.025 (0.635) NOMINAL
RECOMMENDED PC BOARD FINISHED HOLE DIAMETER:
0.042 ±0.003 (1.067 ±0.076)
(LSD) DIGIT DRIVE 5
(MSD) DIGIT DRIVE 1
DIGIT DRIVE 2
DIGIT DRIVE 3
DIGIT DRIVE 4
POLARITY
A
B
C
D
E
F
+5V SUPPLY
DISPLAY TEST
5V RETURN
DP3
DP2
DP1
1
2
3
4
5
6
A
B
C
D
E
F
FRONT VIEW
L
K
J
I
H
G
DP1
0.92
(23.37)
0.84
(21.34)
DP2
DP3
2.17
(55.12)
2.09
(53.09)
DP4
0.040
(1.02)
0.040
(1.02)
0.17
(4.32)
TYP.
0.10
(2.54)
TYP.
0.50
(12.70)
0.040
(1.02)
1.60
(40.64)
1.80
(45.72)
OPTIONAL BEZEL (DMS-BZL1 and DMS-BZL2)
#2-56 INSERT
0.156 (3.96) DEEP
0.187
(4.75)
BEZEL INSTALLATION
FRONT VIEW
LEZ B
2.55 (64.77)
RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS
INTERNAL CORNER RADII:
0.032 (0.81) MAX.
0.116
(2.95)
RETAINING CLIP INSTALLATION
1.07
(27.18)
PANEL CUTOUT
0.878
(22.30)
LENAP
2.35 (59.69)
0.093 (2.362) DIAMETER (4 REQUIRED)
ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY
0.096
(2.44)
®
®
ISO 9001
R E G I S T E R E D
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com
Email: sales@datel.com
Data sheet fax back: (508) 261-2857
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
®
®
2.118 (53.80)
®
®
1.270
(32.26)
®
A S U NI E D A M
®
MECHANICAL DIMENSIONS: Inches (mm)
TOLERANCES: 2 PL DEC ±0.02 (±0.51)
3 PL DEC ±0.010 (±0.254)
DSD-40BCD-XX
12
11
10
9
8
7
N.C.
N.C.
5V RETURN
N.C.
DP4
N.C.
L
K
J
I
H
G
B4
B2
B1 (LSB)
B8 (MSB)
N.C.
N.C.
0.56
(14.22)
0.250 (6.35) TYP.
0.10
(2.54) TYP.
0.145
(3.68) TYP.
PIN #1
IDENTIFIER
LENAP
DS-0335A 1/98
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