SIMPLIFIED SCHEMATIC
Figure 1. Simplifi ed Schematic
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 fi lter 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
PRODUCT OVERVIEW
Murata Power Solutions' 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 fi lter/bezel) to imple-
ment 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 fl exible 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 inter-
face directly with most BCD output, integrating 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 benefi t from the superior readability offered by LED displays.
B2
B4
B1
N.C.
N.C.
DIGIT
DRIVE 5
F
E
DI
K
L
J
H
G
A
C
B
B8
SEVEN-SEGMENT DRIVERS
DISPLAY TEST
ABCDEFG
+5V
POL
+5V SUPPLY
DP 1
DP 2
DP 3
6
5
4
1
3
2
5V RETURN
DISPLAY TEST DIGIT
DRIVE 1
DIGIT
DRIVE 2
DIGIT
DRIVE 3
DIGIT
DRIVE 4
DIGIT
DRIVE 4
DIGIT
DRIVE 1
N.C.
N.C.
5V RETURN
DP 4
N.C.
9
11
12
10
8
7
N.C.
DIG 5DIG 4DIG 3DIG 2DIG 1
POLARITY
DP
BCD DECODER
DP1 DP2 DP3 DP4
DP 1 DP 4
A
B
C
D
E
FG
Segment
Identification
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DSD-40BCD Series
Miniature 4½ Digit, BCD Input, Slave LED Display
MPM_DSD-40BCD.C01 Page 1 of 5
Functional Specifi cations
TA = +25°C and supply voltage = +5V, unless otherwise noted.
Control Inputs Min. Typ. Max. Units
BCD (pins I-L) and TEST (pin 2) Inputs:
Low-Level Input Voltage (VIL) – – +0.8 Volts
Low-Level Input Current (IIL) – – 0.4 mA
High-Level Input Voltage (VIH) +2.4 – – Volts
High-Level Input Current (IIH) – – 0.05 mA
Polarity Input (pin F):
Low-Level Input Voltage (VIL) – – +0.8 Volts
Low-Level Input Current (IIL) – – 0.4 mA
High-Level Input Voltage (VIH) +4.5 – – Volts
High-Level Input Current (IIH) – – 0.05 mA
Digit Drive Inputs (pins A-E):
Low-Level Input Voltage (VIL) – – +0.8 Volts
Low-Level Input Current (IIL) – – 0.4 mA
High-Level Input Voltage (VIH) +4.5 – – Volts
High-Level Input Current (IIH) – – 2 mA
DP1-DP4 Inputs (pins 4-6, 8):
Low-Level Input Voltage (VIL) – – +0.8 Volts
Low-Level Input Current (IIL) – – 20 mA
High-Level Input Voltage (VIH) +4.5 – – Volts
High-Level Input Current (IIH) – – 0.05 mA
Power Supply Requirements
Supply Voltage +4.75 +5.00 +5.25 Volts
Supply Current:
DSD-40BCD-GS – +100 +130 mA
DSD-40BCD-RL – +35 +45 mA
DSD-40BCD-RS – +85 +110 mA
Ordering Information
DSD-40BCD - RS-C
LED Color: GS = Standard Green
RL = Low-Power Red
RS = Standard Red
Accessories:
DMS-30-CP Panel cutout punch
DMS-BZL1-C DSD-40 bezel assembly
DMS-BZL2-C DSD-40 bezel assembly with sealing gasket
A panel-mount retaining clip is supplied with each model.
Display Min. Typ. Max. Units
Display Type and Size 4½ Digit LED, 0.52"/13.2mm high
LED Peak Wavelength (λ):
DSD-40BCD-GS – 565 – nm
DSD-40BCD-RL – 630 – nm
DSD-40BCD-RS – 635 – nm
Physical/Environmental
Operating Temperature 0 – +70 °C
Storage Temperature –40 – +75 °C
Humidity (Non-condensing) 0 – 85 %
Case Material Polycarbonate
Weight 1 ounce (28 grams)
BCD Inputs and Resultant Displays
0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111
TECHNICAL NOTES
1. DSD-40BCD Operation (Please Refer to the Timing and Pinout Dia-
grams for the Following Discussion): The DSD-40BCD display has fi ve
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 fi ve digits and only one set of BCD data in-
puts, the DSD-40BCD's digits have their segments tied ("multiplexed")
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 sec-
tion titled "Controlling the Display Brightness."
2. DSD-40BCD Timing Diagram (See Figure 2): The timing diagram de-
picts 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 fi gure 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
See www.murata-ps.com/dpm-availability for model-specifi c availability.
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DSD-40BCD Series
Miniature 4½ Digit, BCD Input, Slave LED Display
MPM_DSD-40BCD.C01 Page 2 of 5
sequence can be used, as long as BCD data is presented at the cor-
rect 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 specifi cations 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 specifi ed minimum VIH 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 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 compo-
nents 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 fi ve
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
signifi cant enough to justify any timing changes.
6. Highlighting Selected Digits: In many instrument designs, it is
sometimes desirable to highlight or "fl ash" 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 fl ash the digit on and off, at a 0.5 to 1Hz rate, with the DIGIT
DRIVE input. Keeping the duty cycle fi xed at 20% for 5-digit applica-
tions, and 25% for 4-digits, will keep the intensity of the non-fl ashed
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 Murata Power Solutions' DMS-40PC-X-RS-BCD Se-
ries, 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 fi ve 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 solder-
ing techniques may have on the display's polycarbonate case and
overall performance. We also recommend 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 Murata Power Solutions P/N 4320-01074-0
Panel mounted: Murata Power Solutions 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) 812-944-6733 Fax: 812-948-5047
Europe (Scotland) 01236-739292 Fax: 01236-727113
Asia (Singapore) 65-745-5955 Fax: 65-841-1502
www.murata-ps.com/support
DSD-40BCD Series
Miniature 4½ Digit, BCD Input, Slave LED Display
MPM_DSD-40BCD.C01 Page 3 of 5
Figure 2. BCD Data Timing Diagram
Notes:
1. Maximum allowable digit-to-digit overlap is 5μsec.
2. Maximum allowable digit-to-BCD data skew is also 5μsec.
DIGIT DRIVE 1
(MSD)
DIGIT DRIVE 2
DIGIT DRIVE 3
DIGIT DRIVE 4
DIGIT DRIVE 5
(LSD)
BCD DATA
(4 LINES)
Approx. 2msec
Approx. 2msec
Approx. 8msec
1
MSD
234 5
LSD
12345
MECHANICAL SPECIFICATIONS
MECHANICAL DIMENSIONS: Inches (mm)
TOLERANCES: 2 PL DEC ±0.02 (±0.51)
3 PL DEC ±0.010 (±0.254)
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)
B4
B2
B1 (LSB)
B8 (MSB)
N.C.
N.C.
DSD-40BCD-XX
FRONT VIEW
+5V SUPPLY
DISPLAY TEST
5V RETURN
DP3
DP2
DP1
1
2
3
4
5
6
N.C.
N.C.
5V RETURN
N.C.
DP4
N.C.
12
11
10
9
8
7
DP1 DP2 DP3 DP4
2.17
(55.12)
2.09
(53.09)
1.80
(45.72)
0.250 (6.35) TYP.
0.145
(3.68) TYP.
0.040
(1.02)
0.10
(2.54)
TYP.
0.040
(1.02) 0.17
(4.32)
TYP. 0.50
(
12.70
)
0.84
(21.34)
0.92
(23.37)
PIN #1
IDENTIFIER
0.56
(14.22)
(LSD) DIGIT DRIVE 5
(MSD) D IG IT D RIVE 1
DIGIT DRIVE 2
DIGIT DRIVE 3
DIGIT DRIVE 4
POLARITY
A
B
C
D
E
F
L
K
J
I
H
G
1.60
(40.64) 0.10
(2.54) TYP.
A
B
C
D
E
F
L
K
J
I
H
G
0.040
(1.02)
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DSD-40BCD Series
Miniature 4½ Digit, BCD Input, Slave LED Display
MPM_DSD-40BCD.C01 Page 4 of 5
MECHANICAL SPECIFICATIONS, CONT.
#2-56 INSERT
0.156 (3.96) DEEP
FRONT VIEW
1.270
(32.26)
0.187
(4.75)
OPTIONAL BEZEL (DMS-BZL1 and DMS-BZL2)
2.35 (59.69)
2.118 (53.80)
0.093 (2.362) DIAMETER (4 REQUIRED)
ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY
RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS
INTERNAL CORNER RADII:
0.032 (0.81) MAX.
1.07
(27.18) 0.878
(22.30)
0.096
(2.44)
0.116
(2.95)
2.55 (64.77)
PANEL CUTOUT
PANEL
PANEL
BEZEL
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Murata Power Solutions, Inc. 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. Specifi cations are subject to change without
notice. © 2015 Murata Power Solutions, Inc.
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfi eld, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
This product is subject to the following operating requirements
and the Life and Safety Critical Application Sales Policy:
Refer to: http://www.murata-ps.com/requirements/
DSD-40BCD Series
Miniature 4½ Digit, BCD Input, Slave LED Display
MPM_DSD-40BCD.C01 Page 5 of 5
