DMS-20PC DMS-20PC-0 DMS-20PC-1 DMS-20PC-2 DMS-20PC-3 DMS-20-CP DMS-20 - Datasheet Archive
® DMS-20PC Series 3½ Digit, LED Display Low-Cost, Subminiature Digital Panel Voltmeters Actual Size Features ·
® ® DMS-20PC DMS-20PC Series 3½ Digit, LED Display Low-Cost, Subminiature Digital Panel Voltmeters Actual Size 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 · DISPLAY ENABLE function for "power-down" mode · DISPLAY TEST and HOLD (optional) functions · 0 to +60°C temperature range DMS-20PC DMS-20PC Series, 3½ 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 subminiature (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 +60°C. The meters come with one of four, differential, input voltage ranges: ±200mV, ±2V ±20V or ±200V. Input impedance is a minimum 800k. 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 "powerdown" 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 DMS-20PC Series the best choice for all your 3½ digit, LED, DPM applications. +5V 1 12 V+ +5V SUPPLY () INPUT LO 0.01 µF 5V DISPLAY 2 ENABLE 2 R2 1 R1 DC/DC CONVERTER 11 (+) INPUT HI V 909k » +2.0V 3 5V RETURN 0 Vdc 4 10 ANALOG COMMON A/D CONVERTER DATA 9 DISPLAY 3 TEST/HOLD DP 3 8 5 REFERENCE OUT +5V DP 2 6 7 DP 1 REFERENCE IN 1 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. 2 Only used on ±200mV (-0) and ±2V (-1) models. 3 Pin 9 is DISPLAY TEST on all but four models. On those models (-H option), it is DISPLAY HOLD. Figure 1. DMS-20PC DMS-20PC Series Simplified Schematic DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) · Tel: (508) 339-3000 Fax: (508) 339-6356 · For immediate assistance: (800) 233-2765 DMS-20PC DMS-20PC 3 ½ D I G I T , L E D D I S P L AY D I G I T A L P A N E L V O L T M E T E R S Performance/Functional Specifications Typical at TA = +25°C and supply voltage = +5V using the single-ended input circuit, unless otherwise noted. Analog Inputs Full Scale Input Range: DMS-20PC-0 DMS-20PC-0 DMS-20PC-1 DMS-20PC-1 DMS-20PC-2 DMS-20PC-2 DMS-20PC-3 DMS-20PC-3 Input Impedance: DMS-20PC-0 DMS-20PC-0, -1 DMS-20PC-2 DMS-20PC-2, -3 Min. Typ. Max. - ±200 ±2 ±20 ±200 - mV Volts Volts Volts 100 0.8 1000 1 - Ordering Information Units M M Overvoltage Protection - - ±250 - - ±2 Volts CMRR (dc to 60Hz) - 86 - Input Range: 0 = ±200mV 1 = ±2V 2 = ±20V 3 = ±200V dB Leave blank for standard models. Add -H for DISPLAY HOLD option (available on standard red LED models only). Volts Common Mode Voltage Range DMS-20PC DMS-20PC - 1 - RS LED Color: AS = Standard Amber GS = Standard Green OS = Standard Orange RS = Standard Red Control Inputs Decimal Point Placement (Pins 4-6) Tie to pin 3 to activate Display Test (Pin 9) Tie to pin 3 to activate all segments Display Hold (Pin 9) Accessories: DMS-20-CP DMS-20-CP DMS-BZL3 DMS-BZL4 DMS-EB2 Tie to pin 3 to hold last reading Performance Sampling Rate Accuracy (3 minute warm-up): DMS-20PC-0 DMS-20PC-0 (VIN = +0.19V) DMS-20PC-1 DMS-20PC-1 (VIN = +1.9V) DMS-20PC-2 DMS-20PC-2 (VIN = +19V) DMS-20PC-3 DMS-20PC-3 (VIN = +190V) Zero Reading (VIN = 0 Volts) Temperature Drift (0 to +60°C) 2.5 samples per second - ±1 ±1 ±2 ±2 ±3 ±3 ±3 ±3 Counts Counts Counts Counts " 001" "000" "001" - ±0.2 ±0.4 Cnts/°C Supply Voltage +4.75 +5.00 +5.25 Volts - +60 +7 +90 +90 +90 +90 +60 +60 +90 +12 +120 +120 +120 +120 +90 +90 mA mA mA mA mA mA mA mA 1. REFERENCE OUTPUT (Pin 8) and INPUT (Pin 7): Pin 8 is 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. It is 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 system's analog ground. 3. Decimal Point Placement: The location of the decimal point is user-selectable, and the decimal point control pins (DP1-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 left open. Display Display Type and Size 3½ Digit LED, 0.37"/9.4mm high Polarity Indication Autopolarity ("" for negative VIN) Overrange Indication "1_ " for negative VIN "1_" for positive VIN 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: Physical/Environmental Operating Temperature Storage Temperature Humidity (Non-condensing) Case Material Weight Panel cutout punch DMS-20 DMS-20 bezel assembly DMS-20 DMS-20 bezel assembly with sealing gasket Application/evaluation board with standard MOLEX connector, decimal point solder pads and attenuation resistor pads. Technical Notes Power Supply Requirements Supply Current: DMS-20PC-X-RS DMS-20PC-X-RS DMS-20PC-X-RL DMS-20PC-X-RL DMS-20PC-X-AS DMS-20PC-X-AS DMS-20PC-X-GS DMS-20PC-X-GS DMS-20PC-X-OS DMS-20PC-X-OS DMS-20PC-X-YS DMS-20PC-X-YS DMS-20PC-X-RS-H DMS-20PC-X-RS-H DMS-20PC-X-RH DMS-20PC-X-RH YS = Standard Yellow RH = High-Intensity Red RL = Low-Power Red 0 - +60 °C 40 - +75 °C 0 - 95 % Model Applied "0" Voltage DMS-20PC-X-RL DMS-20PC-X-RL +0.05V max. All Others +0.4V max. Polycarbonate 0.4 ounces (11 grams) Load Current* 0.7mA max. 6mA max. * The driving gates must be able to sink this much current (IOL) with a logic "0" output. Applies for transient or continuous overvoltages applied to (+) INPUT HI (pin 11) 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. See Ordering Information. 2 DMS-20PC DMS-20PC 3½ D I G I T , L E D D I S P L A Y D I G I TA L P A N E L V O L T M E T E R S 4. DISPLAY TEST/HOLD (Pin 9) Function: Pin 9 is a dualfunction 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, will be illuminated. The display will show "1888" ("1888" if a negative input signal is present). Do not leave the meter in the 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 not being used. 8. Suggested Mating Connectors: Panel mounted: Connector housing Terminal type Crimping tool Wire size Insulation diameter Stripping length Board mounted: Socket On models with the "-H" suffix (DMS-20PC-1-RS-H DMS-20PC-1-RS-H for example), 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 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 calibrated operation before holding a new reading. MOLEX P/N 22-01-2061 MOLEX P/N 08-65-0805 MOLEX P/N 11-01-0037 22 to 26 AWG 0.062" (1.57mm) maximum 0.100 to 0.125" (2.54 to 3.17mm) SAMTEC P/N SSW-106-02-T-S SSW-106-02-T-S Applications DMS-20PC DMS-20PC meters are highly versatile devices that can be used in hundreds of applications. The application circuits chosen for this section are ones that have historically received many inquiries. The DISPLAY TEST or DISPLAY HOLD pin should normally be connected, via a selector switch, to pin 1 (+5V SUPPLY). If automatic, logic-controlled operation is desired, only PNP or MOSFET transistors should be used. The base or gate of these transistors should be driven sufficiently hard to bring pin 9 within 0.05V of +5V SUPPLY. The schematic in Figure 1 shows that the meter's high-impedance input consists of an op amp powered from a ±5Vdc power supply (the 5V is internally generated). One can easily see why input signals applied to () INPUT LO and (+) INPUT HI have to be kept within the power supply rails of ±5V. Also note that only pin 11 has a current-limiting 909k series resistor. High input voltages that have a common ground with pin 3 (5V RETURN) should only be applied to pin 11 (+) INPUT HI) and never to pin 12. In these high-voltage cases, pin 12 should always be tied to pin 3 (5V RETURN). 5. DISPLAY ENABLE (Pin 2) Function: On all models, tying pin 2 to pin 1 (+5V SUPPLY) applies full power to the LED display. This is the normal mode of operating the meter. Leaving DISPLAY ENABLE open (no connection), only turns off the LED display. The meter's analog-to-digital converter continues to sample the input signal. Total current consumption with the display off is approximately 400µA (0.4mA). This is a very useful feature if the meter is used in battery-powered equipment. The schematic also shows that pin 3 is the meter's zero-volt reference point - regardless of the type of power or signal source used. This is an important point to keep in mind when a digital or analog multimeter is used to make system measurements. The multimeter's negative lead (usually the black one) must be connected to pin 3 (5V RETURN). With the exception of the low-power red led models (DMS20PC-X-RL DMS20PC-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-20PCX-RH DMS-20PCX-RH model. All low-power red LED models must have DISPLAY ENABLE tied directly to pin 1 (+5V SUPPLY). Voltages applied to DISPLAY ENABLE must never be greater than +5V SUPPLY. 1. Single-Ended Input Configurations: True single-ended measurements can be made with any DMS-20PC DMS-20PC meter. The circuit of Figure 2 avoids problems normally associated with ground-loop currents. Separate ground runs should be used for 5V RETURN (pin 3) and () INPUT LO (pin 12). 6. Gain Adjust: There is a gain-adjust potentiometer on the back of each meter. It has approximately ±50 counts (±2.5%) range of adjustment. Since these devices essentially have no zero/ offset errors, a gain adjustment is effectively an overall accuracy 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 Figure 9 provides ±10% range of adjustment. DMS-20PC-1 DMS-20PC-1 11 (+) IN HI 8 REF OUT + VIN 12 () IN LO 7 REF IN 1 +5V SUP 7. Soldering Methods: All models in the DMS-20PC DMS-20PC Series easily withstand most common wave soldering operations. We recommend, however, that you evaluate the effects your particular soldering techniques may have on the meter's plastic case and high-precision electrical performance. We recommend the use of water-soluble solders and thorough cleaning procedures. 120 VAC 2 6 3 DISPLAY ENABLE DP1 5V RET DATEL UPA-5/500 UPA-5/500 AC to DC Converter Figure 2. Single-Ended Input Configuration 3 DMS-20PC DMS-20PC 3 ½ D I G I T , L E D D I S P L AY D I G I T A L P A N E L V O L T M E T E R S Applications to () INPUT LO (pin 12) provides the reference point for the meter's input. 2. Differential Input Configurations: Differential measurements can be made with all DMS-20PC 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 DMS-20PC-1 DMS-20PC-1 DMS-20PC-1 11 (+) IN HI R1 1k 11 (+) IN HI REF OUT 8 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. 8 REF OUT + REF IN 12 () IN LO 7 DP1 6 2 +5V SUP 1 R3 1k 5V RET +5V SUP 2 3 6 DISPLAY ENABLE 5V RET DP1 DATEL UPA-5/500 UPA-5/500 120 VAC DATEL UPA-5/500 UPA-5/500 120 VAC 12 () IN LO 7 REF IN 3 DISPLAY ENABLE 1 1.5V CELL R2 1k AC to DC Converter AC to DC Converter Figure 3. Differential Input Configuration Figure 5. Floating Input Measurements 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. R1 and R2 should be precision, ±1%, metal-film resistors with absolute TCR's less than 50ppm/°C. DMS-20PC-1 DMS-20PC-1 11 (+) IN HI + 1.5V CELL 8 REF OUT 10 ANA COMM 12 7 REF IN () IN LO 50k < R1 + R2 < 10M 1 +5V SUP R2 6 DISPLAY ENABLE 5V RET DP1 120 VAC DATEL UPA-5/500 UPA-5/500 + AC to DC Converter R1 DMS-20PC-1 DMS-20PC-1 11 (+) IN HI R2 Figure 6. Floating Input Measurements (Alternate Configuration) 8 REF OUT VIN 12 () IN LO 5. 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 DMS-20PC meters have such high input impedance, a simple shunt resistor across the meter's 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: 7 REF IN 1 +5V SUP 120 VAC 3 x VIN = Reading R1 + R2 2 2 3 DISPLAY ENABLE 5V RET DATEL UPA-5/500 UPA-5/500 AC to DC Converter Figure 4. Input Attenuation Circuit RShunt = R1 = VFsr / I Fsr 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 (5V RETURN) Where: VFsr = Full scale reading (in Volts) I Fsr = Relative full scale current (in Amps) 4 DMS-20PC DMS-20PC 3½ D I G I T , L E D D I S P L A Y D I G I T A L P A N E L V O L T M E T E R S Applications The LM-2931 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 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. 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), V Fsr = 1.000 Volts RShunt = 1.000V/(0.020 0.004)A RShunt = 1.000V/0.016A = 62.5 Ohms 7. 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 0.1 current shunt. The circuit shown represents a basic ammeter connection diagram. A detailed application note describing digital dc ammeters is included in DATEL's new Digital Panel Meter Databook. 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 RShunt accordingly. 11 (+) IN HI DMS-20PC-1 DMS-20PC-1 8 REF OUT + 10 ANA COMM 1 +5V SUP 12 R1 4-20mA 7 REF IN () IN LO 1 + 5VDC 2 3 DISPLAY ENABLE +5V SUP R2 5V RET 8 REF OUT 3 5V RET 50k 6 DP1 DATEL UPA-5/500 UPA-5/500 120 VAC DMS-20PC-0 DMS-20PC-0 2 DISP EN 7 REF IN 11 (+) IN HI 12 () IN LO 0.150V 1.5 Amp (Load Current) AC to DC Converter Load (3.3 W ) 0.1W RShunt Figure 7. 4-to-20mA Current Loop Operation Figure 9. DC Ammeter Circuit 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 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, threeterminal regulator (LM-2931Z-5 LM-2931Z-5, available from National Semiconductor) to provide regulated 5V-power to the meter. 8. 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. OUT 12 VOLTAGE CALIBRATOR DMS-20PC-2-RL DMS-20PC-2-RL IN 4.5 - 18Vdc 22µF 10V 3 5V RET 1 +5V IN COM 1 +5V SUP OUT GND DMS-20PC-1 DMS-20PC-1 12 LM2931Z-5 LM2931Z-5 + 11 (+) IN HI + Connections for ±2V, ±20V and ±200V models () IN LO 11 (+) IN HI 10 ANA COMM 2 DISP_EN 8 NC 7 REF IN 8.06k, 1% 3 5V RET 2k 1 17.4k, 1% 5 DP2 7 REF IN 8 REF OUT 12 () IN LO 732, 1% 200 1 1 24.3k, 1% = 10 to 20 Turns Figure 8. 4.5V -18V Power Supply Monitor Figure 10. External Gain Adjustment 5 Connections for ±200mV models DMS-20PC DMS-20PC 3½ D I G I T , L E D D I S P L A Y D I G I TA L P A N E L V O L T M E T E R S Mechanical Specifications PIN #1 IDENTIFIER DMS-20PC-X-XX DMS-20PC-X-XX MADE IN USA RECOMMENDED PC BOARD FINISHED HOLE DIAMETER: 0.042 ±0.003 (1.067 ±0.076) TOP VIEW +5V SUPPLY DISPLAY ENABLE 5V RETURN DP3 DP2 DP1 CALIBRATION POTENTIOMETER HOLE LOCATION 0.125 (3.175) DIAMETER (USE ONLY WHEN PC BOARD MOUNTING) PIN 1 ® LEAD DIMENSIONS: 0.025 (0.635) x 0.025 (0.635) NOMINAL ® MECHANICAL DIMENSIONS: Inches (mm) TOLERANCES: 2 PL DEC ±0.02 (±0.51) 3 PL DEC ±0.010 (±0.254) 12 11 10 9 8 7 1 2 3 4 5 6 DP1 0.170 (4.32) DP2 0.88 (22.4) DP3 1.38 (35.0) 0.80 (20.3) () INPUT LO (+) INPUT HI ANALOG COMMON DISPLAY TEST/HOLD REFERENCE OUT REFERENCE IN 1.30 (33.0) 0.150 (3.81) 0.475 (12.0) 0.040 (1.02) 0.250 (6.35) TYP. 0.040 (1.02) 0.15 (3.81) TYP. 0.10 (2.54) TYP. 1.10 (27.9) 0.040 (1.02) 0.10 (2.54) TYP. 0.50 (12.70) PANEL RETAINING CLIP (Supplied) OPTIONAL BEZEL (DMS-BZL3 and DMS-BZL4) 1.71 (43.43) #2-56 INSERT 0.156 (3.96) DEEP 0.187 (4.75) BOTTOM VIEW 1.21 (30.73) 1.07 (27.18) 0.60 (15.24) 1.280 (32.51) DATEL, INC. RETAINING CLIP INSTALLATION 1.21 (30.734) 0.10 (2.54) 1.626 (41.3) 0.10 (2.54) 1.826 (46.38) PANEL RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS INTERNAL CORNER RADII: 0.062 (1.57) MAX. ® ® 1.07 (27.18) 0.838 (21.28) ISO 9001 R E G I S T E R E D 1.336 (33.96) 1.626 (41.3) ® ® 0.093 (2.362) DIAMETER (4REQUIRED) ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY 0.145 (3.68) 0.116 (2.94) DS-0271A DS-0271A DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 Tel: (508) 339-3000 / Fax: (508) 339-6356 For immediate assistance: (800) 233-2765 10/96 DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 DATEL S.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 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.