D OATEL INNOVATION and EXCELLENCE DMS-20PC Series 3% Digit, LED Display Low-Cost, Subminiature Actual Size Digital Panel Voltmeters Features Lowest-cost LED meters Subminiature size: 1.38" x 0.88" x 0,48 35mm x 22mm x 12mm Large (0.37"/9.4mm) LED display Choice of 5 LED colors * High-intensity or low-power (7mA) red LED's optional * Epoxy-encapsulated, 12-pin DIP package with built-in color filter and bezel 4 differential input voltage ranges Factory calibrated, +1 count accuracy Single +5V power supply * User-selectable decimal point placement e DISPLAY ENABLE function for power-down" mode DISPLAY TEST and HOLD (optional) functions * 0 to +60C temperature range DMS-20PC Series, 3'% Digit, LED Display, Digital Panel Voltmeters combine a precision A/D converter; a factory-trimmed, highly stable, voltage reference; and a large (0.37'/9.4mm), easy-to-read LED display in a single package that is only slightly larger than the display itself. Displays are offered in either red, orange, amber, yellow or green colors. High-intensity and low-power (35mW total) red LED's are also optional. These low-cost meters are fully self-contained and fully functional. Their submin- iature (1.38" x 0.88 x 0.48"), epoxy-encapsulated cases incorporate built-in color filters and bezels; are moisture and vibration proof; and function well in the harshest environments. Their 12-pin, dual-in-line configuration offers component-like, plug-in convenience and maximum versatility. Operating temperature range is 0 to +60C. The meters come with one of four, differential, input voltage ranges: t200mV, +2V +20V or +200V. Input impedance is a minimum 800kQ. CMRR is typically 86dB (dc to 60Hz), and CMV is +2V. Input overvoltage protection (on the non-inverting input) is +250V. Devices are fully calibrated at the factory to an accuracy of +1 count (+0.05% of full scale range) and never require calibration or adjustment. A DISPLAY ENABLE function permits the display to be disabled for "power- down" operation. All models have a DISPLAY TEST function. Red LED models offer an optional DISPLAY HOLD function. Small size, low cost and adjustment-free reliability make the DMS-20PC Series the best choice for all your 3'% digit, LED, DPM applications. rp +5V 12 1 +5V SUPPLY O (-) INPUT LO rc | | a DISPLAY 2 RI ENABLE CONVERTER [, AAA (+) INPUT HI : 909k 3 10 a! ANALOG 5V RETURN po ANALOG 9 pispLay TEST/HOLD 8 REFERENCE OUT > | | 7 \ \________-_- REFERENCE IN| oe @ R2 is not used on +200mV (-0) models or +2V (-1) models. R2 = 100k on +20V {-2) models and 9.1k on 200V (-3) models. @ Only used on +200mV (-0) and +2V (-1) models. @ Pin 9 is DISPLAY TEST on ail but four models. On those models (-H option), itis DISPLAY HOLD. Figure 1, DMS-20PC Series Simplified Schematic DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1194 (U.S.A.) * Tel: 508-339-3000 Fax: 508-339-6356 For immediate assistance 800-233-27653" Performance/Functional Specifications Typical at Ta = +25C and supply voltage = +5V using the single-ended input circuit, unless otherwise noted. Analog Inputs Full Scale Input Range: DMS-20PC-0 DMS-20PC-1 DMS-20PC-2 DMS-20PC-3 Input Impedance: DMS-20PC-0, -1 DMS-20PC-2, -3 0.8 Overvoltage Protection @ |= T= | er] Volts Common Mode Voltage Range |. [= Te] Volts CURR 0 6h Pe Te Control Inputs 2 2 Decimal Point Placement (Pins 4-6) Tie to pin 3 to activate Display Test (Pin 9) Display Hold (Pin 9) @ Performance Sampling Rate 2.5 samples per second +H Accuracy (3 minute warm-up): DMS-20PC-0 (Vin = +0.19V) + 43 DMS-20PC-1 (Viv = 44 OV) DMS-20PC-2 (Vin = +19V) DMS-20PC-3 (Vin = +190V) Zero Reading (Vin = 0 Volts) Temperature Drift (0 to +60C) Power Sy ace ici es Supply Voltage | Counts Counts Counts Counts z oS oO = Supply Current: DMS-20PC-x-RS DMS-20PC-X-RL DMS-20PC-X-AS DMS-20PC-X-GS DMS-20PC-X-OS DMS-20PC-X-Y DMS-20PC-X-RS-H DMS-20PC-X-RH Display Display Type and Size 3 Digit LED, 0.3749.4mm high Polarity Indication Autopolarity ("-" for negative Vin) Overrange Indication 1___ "for positive Viy Meuse et en Humidity (Non-condensing) | % | Case Material Polycarbonate 0.4 ounces (11 grams) mA i Operating Temperature Storage Temperature ! Applies for transient or continuous Overvoltages applied to (+) INPUT HI (pin 1 1) with (-) INPUT LO {pin 12) at 0 Volts. Pin 12 is not overvoltage protected. Voltages applied to pin 12 should not exceed the supply voltage. See Technical Notes. @ The DISPLAY HOLD function is optional on standard red LED models only. DIGIT, LED DISPLAY DIGITAL PANEL VOLTMETERS eee Tenement DMS-20PC-1-RS Input Range: _| | 0=+200mv Leave blank for standard 1=+2V models. 2=+20V Add -H for DISPLAY 3 = +200V HOLD option (available on standard red LED models only), LED Color: AS = Standard Amber YS = Standard Yellow GS = Standard Green RH = High-Intensity Red OS = Standard Orange RL = Low-Power Red RS = Standard Red Accessories: DMS-20-cP Panel cutout punch DMS-BZL3 DMS-20 bezel assembly DMS-BZL4 DMS-20 bezel assembly with sealing gasket DMS-EB2 Application/evaluation board with standard MOLEX connector, decimal Point solder pads and attenuation resistor pads. Technical Notes 1, REFERENCE OUTPUT (Pin 8) and INPUT (Pin 7): Pin 8is a precision reference actively trimmed at the factory. In normal operation, pin 8 must be tied to pin 7 to achieve all listed accuracy and drift specifications, 2. ANALOG COMMON (Pin 10): This pin is connected to an internal, low-noise, relative ground. {tis used in certain differential and "floating" measurements as described in the Applications section of this data sheet and the DATEL Panel Meter Catalog. Pin 10 should not be connected to pin 3 (5V RETURN) or to your syStems analog ground. 3. Decimal Point Placement: The location of the decimal point is user-selectable, and the decimal point control pins (DP -DP3) are active low functions. Select the appropriate decimal point by tying the appropriate pin (pin 4, 5 or 6) to pin 3 (5V RETURN). Unused decimal point location pins should be lett open. Hard wiring is preferable, however, you can use logic gates to exercise dynamic control over the location of the decimal point if the following drive conditions are met: Model Applied "0" Voltage Load Current* DMS-20PC-xX-RL +0.05V max, 0.7mA max. All Others +0.4V max. 6mA max. * The driving gates must be able to sink this much current (lo.) with a logic "0" output. See Ordering Information, 2DMS-20PC Applications 2. Differential Input Configurations: Differential measurements can be made with all DMS-20PC meters. Figure 3, though not a practical real-world application, uses a voltage divider to demonstrate the concept of a differential input signal. Be careful not to exceed the +2V common mode voltage limitation. DMS-20PC-1 1 " : REF OUT 8 (4) INHI R2 REFIN 7 12 1k HIN Le DPI 6 INGO = Ra 1 2 3 tk $ +5V SUP DISPLAY | V RET ENABLE DATEL 120 VAC | upa-srso0 il AC to DC Converter Figure 3. Differential Input Configuration 3. Engineering Scaling: For measuring voltages greater than the full scale input range of a given meter, the input signal must be attenuated. A simple voltage divider (similar to that shown in Figure 4) will scale the input to within the range of the selected meter. Ri and R2 should be precision, +1%, metal-film resistors with absolute TCR's less than 50ppm/C. 50kQ < Ri + R2 < 10MQ R2 Ri + R2 x Vin = Reading " DMS-20PC-1 (+) IN HI 1 2 +5V SUP DISPLAY ENABLE AG to DC Converter 8 REF OUT DATEL 120 VAC | Upa-5/500 Figure 4. input Attenuation Circuit 4. Floating Signal Source Measurements: Floating signals can be measured using the circuits shown in Figures 5 and 6. Connecting pin 10 (ANALOG COMMON) or pin 3 (6V RETURN) 3% DIGIT, LED DISPLAY DIGITAL PANEL VOLTMETERS to (-) INPUT LO (pin 12) provides the reference point for the meters input. A floating input is a signal that has no galvanic connection to the meter's power supply. In the figures below, the 1.5V battery illustrates a true floating input. 1 DMS-20PC-1 REF OUT + 1.5 CELL 7 REF IN = 1 | 2 6 +5V SUP | DISPLAY OPI ENABLE vzovac | DATEL AC to DC Converter = Figure 5. Floating Input Measurements " DMS-20PC-1 8 {s) IN HI REF OUT + 10 4 1.5V ANA COMM CELL 12 CHINLO REF IN +5V 1 2 SUP DISPLAY | 5V ENABLE AG to DC Converter DATEL 120 VAC | ypa.s/s00 Figure 6. Floating Input Measurements (Alternate Configuration) . Process Control (4-to-20mA) Measurements: In many common process-control applications, a 4-to-20mA current loop is used to transmit information. Because DMS-20PC meters have such high input impedance, a simple shunt resistor across the meters input can be used to convert the loop current to a voltage. See Figure 7. The value of the shunt resistor is a function of the scaling requirements of the particular application and can be calculated using the following equation: Rehunt = Ri = Vesr/ les: Where: Ves = Full scale reading (in Volts) Irs = Relative full scale current (in Amps)3% DIGIT, LED DISPLAY DIGITAL PANEL VOLTMETERS Ea Applications Example: For a meter with a 2V full scale input (1.999 full scale reading} and a desired display reading of "1000" (with an input of 20MA), Ves = 1.000 Volts Renn = 1.000V/(0.020 - 0.004)A Asn = 1.000V/0.016A = 62.5 Ohms To calibrate the circuit of Figure 7, perform the following: 1. With 4mA applied, adjust the 50k potentiometer (R2) to display a reading of "000" (assuming that is the desired reading). 2. With 20mA applied, adjust the gain-adjust potentiometer on the back of the meter to display a reading of "1000". For different full scale readings, alter the value of Rswn accordingly. "1 DMS-20PC-1 (INH i ; 8 REF OUT 50k 20 vac | vPAss00 AC to DC Converter Figure 7. 4-to-20mA Current Loop Operation 6. Power Supply Monitoring: One of the most common digital panel meter applications involves monitoring the output voltage of the system power supply often this supply also powers the meter itself. The low-power, red LED DMS-20PC-2-RL can be configured to allow power supply monitoring over the range of 4.5-18Vdc. The circuit in Figure 8 uses a low-drop-out, three- terminal regulator (LM-29312-5, available from National Semiconductor) to provide regulated 5V-power to the meter. DMS-20PC-2-RL LM2931Z-5 71 (+) IN HI 12 INLO 7 8 REF REF IN OUT Figure 8. 4.5V-18V Power Supply Monitor The LM-2931 was chosen because it has the following on-chip protection features: reverse polarity, short circuit and thermal runaway. When using other, higher-power, DMS-20PC models with three-terminal regulators, be sure to consult the regulator manufacturer's data sheet to ensure the regulator is being utilized safely and correctly. . Digital Ammeter: Digital ammeters are finding ever-increasing usage because analog-style ammeters (moving-vane types) now cost roughly the same as their digital counterparts. Additionally, analog ammeters are not nearly as rugged as modern digital panel voltmeters. Figure 9 illustrates a typical ammeter application. The circuit uses a +200mV input meter the preferred range for most ammeters to measure the voltage developed across a 0.1Q current shunt. The circuit shown represents a basic ammeter connection diagram. A detailed apptication note describing digital dc ammeters is included in DATEL's new Digital Pane! Meter Databook. OMS-20PC-0 Figure 9. DC Ammeter Circuit . External Gain Adjustment: Connect REFERENCE OUT (pin 8) to REFERENCE IN (pin 7) for normal, factory calibrated, Operation. Use the circuit shown in Figure 10 for applications needing external gain adjustment. Calibration is performed with a precise, near-full-scale, input voltage. DMS-20PC-1 OUT VOLTAGE CALIBRATOR Connections for 2V, +20V and 2200V models ' I ' ST i Y i Connections TON Ayn AN ann Anod for 400m models 732, 1% 2007 24. 3k, 1% = 101020 Tums Figure 10. External Gain Adjustment3% DIGIT, LED DISPLAY DIGITAL PANEL VOLTMETERS EE 4, DISPLAY TEST/HOLD (Pin 9) Function: Pin 9 is a dual- 8. Suggested Mating Connectors: function pin. On all standard models (without "-H suffix), tying pin 9 to pin 1 (+5V SUPPLY) activates the meter's DISPLAY TEST feature. All display segments, except the decimal points, Panel mounted: Connector housing MOLEX P/N 22-01-2061 will be illuminated. The display will show "1888" ('-1888" i Terminal type Moree CN 06-66-0806 negative input signal is resent}. Do not leave the meter in the Crimping too! Pek PIN 11-01-0087 g pur signal is p Wire size 22 to 26 AWG test mode for more than 10 seconds as this will cause the meter's operating temperature to rise and possibly affect its performance. Pin 9 must be left open when the test function is Insulation diameter 0.062 (1.57mm) maximum Stripping length 0.100 to 0.125" (2.54 to 3.17mm) not being used. Board mounted: On models with the "-H" suffix (DMS-20PC-1-RS-H for example), Socket SAMTEC PIN SSW-106-02-T-S pin 9 serves as a DISPLAY HOLD control pin. Tying pin 9 to +5V SUPPLY (pin 1) on these models will hold or "freeze" the current Applications display reading indefinitely. Pin 9 must also be left open when the hold function is not being used. After disabling DISPLAY HOLD, allow the meter a full 10 seconds to resume normal DMS-20PC meters are highly versatile devices that can be used in calibrated operation before holding a new reading. hundreds of applications. The application circuits chosen for this The DISPLAY TEST or DISPLAY HOLD pin should normally be section are ones that have historically received many inquiries. connected, via a selector switch, to pin 1 (+5V SUPPLY). If The schematic in Figure 1 shows that the meters high-impedance automatic, logic-controlled operation is desired, only PNP or input consists of an op amp powered from a +5Vde power supply MOSFET transistors should be used. The base or gate of these (the -5V is internally generated). One can easily see why input transistors should be driven Sufficiently hard to bring pin 9 within signals applied to (-) INPUT LO and (+) INPUT HI have to be kept 0.05V of +5V SUPPLY, within the power supply rails of +5V. Also note that only pin 11 has a 5. DISPLAY ENABLE (Pin 2) Function: On all models, tying pin 2 Current-limiting 909kQ series resistor High input voltages that have a common ground with pin 3 (5V RETURN) should only be applied to pin 1 (+5V SUPPLY) applies full to the LED display, Opin t (+ ) applies full power to the display to pin 11 ((+) INPUT Hi} and never to pin 12. In these high-voltage This is the normal mode of Operating the meter. Leaving DISPLAY ENABLE open (no connection), only turns off the LED cases, pin 12 should always be tied to pin 3 (SV RETURN). display. The meter's analog-to-digital converter continues to The schematic also shows that pin 3 is the meter's zero-volt sample the input signal. Total current consumption with the reference point regardless of the type of power or signal source display off is approximately 400uA (0.4mA). This is a very useful used. This is an important point to keep in mind when a digital or feature if the meter is used in battery-powered equipment. analog multimeter is used to make system measurements, The multimeters negative lead (usually the black one) must be With the exception of the low-power red | id models (DMS- OR otis OW Power red led models ( connected to pin 3 (SV RETURN). 20PC-X-RL), a regulated voltage lower than +5V SUPPLY can be used to dim the display intensity. Display intensity control is best performed with the high brightness, red LED, DMS-20PC- 1. Single-Ended Input Configurations: True single-ended X-RH model. All low-power red LED models must have DISPLAY measurements can be made with any DMS-20PC meter. The ENABLE tied directly to pin 1 (+5V SUPPLY). Voltages applied circuit of Figure 2 avoids problems normally associated with to DISPLAY ENABLE must never be greater than +5V SUPPLY. ground-loop currents, Separate ground runs should be used 6. Gain Adjust: There is a gain-adjust potentiometer on the back for SV RETURN (pin 3) and (-) INPUT LO (pin 12). of each meter. It has approximately +50 counts (2.5%) range of adjustment. Since these devices essentially have no zero/ wen " DMS-20PC-1 Offset errors, a gain adjustment is effectively an overall accuracy (+) IN Ht Fer out adjustment. Though they may be performed at any point " (except zero), accuracy adjustments are most effective when _ . performed with higher level input signals. The circuit shown in aa 2 7 : : . (-)INLa REF IN Figure 9 provides +10% range of adjustment, 1 ; 3 7. Soldering Methods: All models in the DMS-20PC Series easily sev suPy dpeetty OP | sv rer withstand most common wave soldering operations. We . DATE! recommend, however, that you evaluate the effects your 120VAC | ypa-sis00 particular soldering techniques may have on the meters plastic -. case and high-precision electrical performance. We recommend AC 10 DC Converter the use of water-soluble solders and thorough cleaning . . _ procedures, Figure 2. Single-Ended Input Configuration37, DIGIT, LED DISPLAY DIGITAL PANEL VOLTMETERS Mechanical Specifications MECHANICAL DIMENSIONS: Inches (mm) TOLERANCES: 2 PL DEC +0.02 (40.51) 3 PL DEC +0.010 (40.254) LEAD DIMENSIONS: 0.025 (0.635) x 0.025 (0.635) NOMINAL RECOMMENDED PC BOARD FINISHED HOLE DIAMETER: 0.042 +0.009 (1.067 +0.076) 0.125 (3.175) DIAMETER PINT o 0.170 (4.32) mel : LT 0.150 (3.81) | CALIBRATION POTENTIOMETER HOLE LOCATION (USE ONLY WHEN PC BOARD MOUNTING) 0.88 (22.4) 0,040 | (4.02) ~ 0.80 (20.3) PIN #1 |iV XXX-Od02-SNO IDENTIFIER yennizovn STSLSOI.G nd TOP VIEW +5V SUPPLY 17 0 cy 4.12 (VINPUTLO DISPLAY ENABLE 2] [2 cp [41 G)INPUTHI 5VRETURN 3] [) (2 | 40 ANALOG COMMON DP3 4) 0 3 9 DISPLAY TEST/HOLD pp2 | G @ REFERENCE OUT oP 6) 3 | cy | 7 REFERENCE IN T Y . 0.475 (12.0) 0.040 (1.02) 0.250 (6.35) TYP. 4 0.10 1.10 (2.54) (273) esa) 0.45 TYP. TYP 0.040 . (3.81) (1.02) TYP. 0.50 (12.70) PANEL RETAINING CLIP (Supplied) OPTIONAL BEZEL 171 (DMS-BZL3 and DMS-BZL4) (43.43) #2-56 INSERT 0.187 0.156 (3.96) DEEP (4.75) BOTTOM VIEW 4.21 1 (30.73) 1.07 0.60 4.280 (27.18) (18.24) (32.51) RETAINING CLIP INSTALLATION tT Pe? a oe 4.24 (30.734) o ! . 2.54 0.10 y (2.54) - 1.626 (41.3) >| = 05) 4.826 (46.38) _>| D DATEL INNOVATION and EXCELLENCE RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS INTERNAL CORNER RADII: 0.062 (1.57) MAX. ao 1.07 (27.18) 0.838 (21.28) 0.145 (3.68) 0.116 (2.94) L_ 1.336 (33.96) arr | 1,626 (41.3) 0.093 (2.362) DIAMETER (4REQUIRED) ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1194 Tel: (508) 339-3000 / Fax: (508) 339-6356 For immediate assistance 1-800-233-2765 DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 DATEL $.A.R.L. Montigny Le Bretonneux, France Tel: 1-34-60-01-01 DATEL GmbH Munchen, Germany Tel: 89-544334-0 DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025 DATEL makes no representation thal the use of its products in the circuits describad 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 licanses to make, use, oF sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark. DS-0271A 12/95/60