DMS-20LCD-2-9B-C

DMS-20LCD Series www.murata-ps.com 3½ Digit, LCD Display Digital Panel Voltmeters FEATURES DMS-20LCD Series, 3½ Digit, LCD Display, Digital Voltmeters represent the ultimate combination of low price, low power, small size and high performance in digital meters. Epoxy encapsulated in a subminiature (1.38” x 0.88” x 0.43”), 12-pin DIP package, these completely self-contained, fully operational meters offer a combination of ruggedness, long-term reliability and component-like ease-of-use simply not available in any other meters.  Lowest cost  Lowest power, 2mW  Subminiature size: 1.38" x 0.88" x 0.43" 35mm x 22mm x 11mm Incorporating a precision reference and a factory-calibrated, autozeroing A/D converter, DMS-20LCD meters are extremely accurate (±1 count) and are only slightly larger than their 0.37"/9.4mm, enhanced-contrast, LCD displays. All models incorporate a built-in bezel and are easily mounted in either panels or pc boards. Both backlit and non-backlit versions are available.  Large (0.37"/9.4mm), enhanced-contrast LCD display  Epoxy-encapsulated, 12-pin DIP  Panel or pc-board mountable  4 differential input voltage ranges DMS-20LCD meters have 4 differential input voltage ranges (±200mV, ±2V, ±20V and ±200V) and a user-friendly input structure. Input impedance is a minimum 800k. CMRR is typically 86dB with a CMV of ±2V. Non-inverting inputs are overvoltage protected to ±100V (±250V for the ±200V input model).  High accuracy, ±1 count (±0.05%)  Single +5V supply or 9V battery  Low-battery annunciator All DMS-20LCD meters operate from a single +5V supply (drawing 400µA) or a single +9V supply/battery (drawing 230µA). All models have a low-battery ("B") annunciator and feature autopolarity changeover and overrange indication.  User-selectable decimal point placement  0 to +60°C temperature range Also available is an application/evaluation board (DMS-EB2) that plugs directly onto the back of any DMS-20LCD allowing direct inputs for common applications such as 4-20mA inputs, zero/gain adjust, decimal point location, and input voltage dividing. SIMPLIFIED SCHEMATIC DIAGRAM +5V +5V SUPPLY/ 1 +BATTERY 12 V+ (–) INPUT LO 2 0.01μF –5V N.C. 2 R2 1 3 R1 DC/DC CONVERTER V– 11 (+) INPUT HI 909k ≈+2.0V 5V RETURN/ 3 –BATTERY J1 10 ANALOG COMMON A/D CONVERTER 0 Vdc DATA DP 3 9 4 N.C./BACKLIGHT 4 8 5 DP 2 REFERENCE OUT +5V 7 6 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. 3 DC/DC converter is not used on 9V-powered models, J1 is connected. 2 Only used on ±200mV (-0) and ±2V (-1) models. 4 Used on backlit models only. N.C. for non-backlit models. 　 For full details go to www.murata-ps.com/rohs www.murata-ps.com/support MPM_DMS20LCD.C01 Page 1 of 6 DMS-20LCD Series 3½ Digit, LCD Display Digital Panel Voltmeters Performance/Functional Specifications Typical at TA = +25°C and supply voltage = +5V (using the single-ended input circuit) or +9V (using the differential input circuit), unless otherwise noted. Analog Inputs Min. Typ. Max. Units Operating Temperature Full Scale Input Range: DMS-20LCD-0 Physical/Environmental – ±200 – mV Storage Temperature DMS-20LCD-1 – ±2 – Volts Humidity (non-condensing) DMS-20LCD-2 – ±20 – Volts Case Material Weight DMS-20LCD-3 – Input Impedence: – ±200 – Volts DMS-20LCD-0, -1 100 1000 – M DMS-20LCD-2, -3 0.8 1 – M Overvoltage Protection ➀ DMS-20LCD-0, -1, -2 – – ±100 Volts DMS-20LCD-3 – – ±250 Volts Common Mode Voltage Range – – ±2 Volts CMRR (dc to 60Hz) – 86 – dB Control Inputs ➁ Decimal Pt. Placement (Pins 4-6) Tie to pin 3 to turn on backlight Sampling Rate 2.5 reading per second DMS-20PC-0 (Vin = +0.19V) – ±1 ±2 Counts DMS-20PC-1 (Vin = +1.9V) – ±1 ±2 Counts DMS-20PC-2 (Vin = +19V) – ±2 ±3 Counts DMS-20PC-3 (Vin = +190V) – ±2 ±3 Counts Zero Reading (Vin = 0 Volts) “–001” “000” “001” – ±0.2 ±0.4 Cnts/°C – +75 °C 0 – 95 % ➀ Applies for transient or continuous overvoltages applied to (+) INPUT HI (pin 11) with (–) INPUT LO (pin 12) properly connected. Pin 12 is not overvoltage protected (see Figure 1). Voltages applied to pin 12 should not exceed the supply voltage. ➁ Listed spec applies to 5V-powered models only. For 9V-powered models, both (–) INPUT LO (pin 12) and (+) INPUT HIGH (pin 11) must always be at least 1.5V above –BATTERY (pin 3) and at least 1.5V below +BATTERY (pin 1). ➂See Technical Notes. Ordering Information -C Input Range: 0 = ±200mV 1 = ±2V 2 = ±20V 3 = ±200V Leave blank for standard models. Add B for backlit models. Power Source: 5 = +5V 9 = +9V +4.75 +5.00 Accessories: DMS-20-CP DMS-BZL3-C DMS-BZL4-C DMS-EB2-C Panel cutout punch DMS-20 bezel assembly DMS-20 bezel assembly with sealing gasket Application/evaluation board with standard MOLEX connector, decimal point solder pads and attenuation resistor pads. A panel-mount retaining clip is supplied with each model. See www.murata-ps.com/dpm-availability for model-specific availability. Power Supply Requirements (5V Models) +5.25 Volts TECHNICAL NOTES Supply Current: Standard Models – +400 +650 µA Backlit Models – +35 +50 mA Power Supply Requirements (9V Models) Supply Voltage –20 Polycarbonate Accuracy (1 minute warm-up): Supply Voltage °C Add -C for RoHS TTL (on 5V-powered models) Performance Temperature Drift (0 = +60°C) +60 Tie to pin 3 to activate Logic Compatibility Backlight (Pin 9) – 0.4 ounces (11 grams) DMS-20LCD - 1 - 5 Tie to pin 3 to activate Functionality 0 +7.5 +9.0 +14.0 Volts Supply Current: Standard Models – +230 +350 µA Backlit Models – +35 +50 mA Display Display Type and Size 3½ digit, 0.37"/9.4mm high LCD Polarity Indication Autopolarity ("–" for negative Vin) Overrange Indication "–1_ _ _ " for negative Vin "1_ _ _ " for positive Vin 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 Ap Note DMS-AN3 at http://www.murata-ps.com/data/meters/dms-an3.pdf. Pin 10 should not be connected to pin 3 (5V RETURN/–BATTERY) or to your system’s analog ground. 3. Decimal Point Placement: The location of the decimal point is userselectable, and the decimal point control pins (DP1-DP3) are active low functions. Select the appropriate decimal point by tying the appropriate www.murata-ps.com/support MPM_DMS20LCD.C01 Page 2 of 6 DMS-20LCD Series 3½ Digit, LCD Display Digital Panel Voltmeters pin (pin 4, 5 or 6) to pin 3 (5V RETURN/–BATTERY). Unused decimal point location pins should be left open. For 5V-powered models, the decimal location pins are TTL compatible and may be hard wired as described above or driven with 5V TTL logic gates. 4. BACKLIGHT (Pin 9) Function: Grounding pin 9 (i.e. connecting it to pin 3) turns on the backlighting LED’s. For non-backlit models, pin 9 has no internal connection. All backlit models include internal currentlimiting resistors. With nominal +5V or 9V supplies, backlit devices typically draw 35mA of supply current. The current drawn by the backlight (and therefore the current drawn by the meter) can be reduced by installing a 1/4 Watt resistor between pins 3 and 9. The brightness of the meter will be reduced proportionately. 9V-powered backlit models function with supply voltages up to +14V, however, activating the backlight with voltages greater than 9.2V can damage the meter. Therefore, a 1/4 Watt series resistor must be installed between pins 3 and 9 in these situations. The value of the series resistor is determined using the following formula: RSeries = +BATTERY – 9.2V 0.035 Ohms Example: If +BATTERY (pin 1 with respect to pin 3) is +12.6V, RSeries = +12.6 – 9.2V 0.035 Ohms RSeries = 97 Ohms 5. Low Battery Annunciator: The “B” annunciator in the upper left-hand corner of the display turns on when the supply voltage for 5V-powered models falls below approximately +3.7V, or when the supply voltage for 9V-powered models falls below approximately 7.2V. However, the lowbattery annunciator’s turn-on threshold can vary significantly from unitto-unit: as low as 2.7V for 5V-powered meters, and as low as 5.4V for 9V-powered models. Applications that use the LOW BAT annunciator must be fully tested by the user, using a combination of low supply voltages and the input signal’s minimum and maximum levels, to ensure that all display readings are valid as long as the LOW BAT annunciator remains off. 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. 8. Suggested Mating Connectors: Panel mounted: Connector housing Terminal type Crimping tool Wire size Insulation diameter Stripping length Board mounted: Socket Murata Power Solutions P/N 4320-01069-0 Murata Power Solutions P/N 4400-01032-0 Murata Power Solutions P/N 39-2099000 22 to 26 AWG 0.062” (1.57mm) maximum 0.100 to 0.125” (2.54 to 3.17mm) Murata Power Solutions P/N 4320-01074-0 APPLICATIONS DMS-20LCD meters are available in either 5V-powered or 9V-powered models. 9V devices operate directly from 7.5V to 14V supplies (usually batteries) without the need for external voltage regulators. 9V devices, however, can not be used to measure voltages referenced to the negative battery terminal (pin 3) because the minus input to the meter (pin 12, (–) INPUT LO) must always be at least 1.5V above pin 3. 9V-powered meters can only be used to make differential and not single-ended measurements. 5V-powered devices operate from any well-regulated +5V supply and will accurately measure voltages both above and below pin 3 (5V RETURN) in either single-ended or differential configurations. 1. Single-Ended Input Configurations: True single-ended measurements can only be made with 5V-powered meters. 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). DMS-20LCD-1-5 11 (+) IN HI + 8 REF OUT VIN – 12 (–) IN LO 7 REF IN 1 +5V SUP 6 3 DP1 5V RET 120 VAC AC to DC Converter Figure 2. Single-Ended Input Configuration (5V-Powered Models) 7. Soldering Methods: All models in the DMS-20LCD 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 no-clean solders. www.murata-ps.com/support MPM_DMS20LCD.C01 Page 3 of 6 DMS-20LCD Series 3½ Digit, LCD Display Digital Panel Voltmeters APPLICATIONS 2. Differential Input Configurations: Differential measurements can be made with either 5V-powered or 9V-powered 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 for 5V powered meters. 8 REF IN 7 11 (+) IN HI 12 (–) IN LO DP1 6 R2 1k R3 1k 3 1 +5V SUP 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. 5V RET DMS-20LCD-1-5 11 (+) IN HI 8 REF OUT + DMS-20LCD-1-5 REF OUT R1 1k 4. Floating Signal Source Measurements: Floating signals can be measured using the circuits shown in Figures 5 and 6. Figure 5 uses a 5V-powered meter. Figure 6 uses a 9V-powered meter. Connecting pin 10 (ANALOG COMMON) to (–) INPUT LO (pin 12) provides the reference point for the meter’s input. 1.5V CELL – 12 7 REF IN (–) IN LO 120 VAC 1 +5V SUP 3 6 5V RET DP1 AC to DC Converter Figure 3. Differential Input Configuration (5V-Powered Models) 120 VAC AC to DC Converter 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. See Ap Note 4 for more information on engineering scaling. 1.5V CELL x VIN = Reading DMS-20LCD-1-9 11 (+) IN HI + 50k < R1 + R2 < 10M R2 Figure 5. Floating Input Measurements (5V-Powered Models) 8 REF OUT 10 ANA COMM – 12 7 REF IN (–) IN LO R1 + R2 1 3 6 –BAT DP1 + + BAT + 9V BATTERY R1 8 REF OUT VIN R2 – – DMS-20LCD-1-5 11 (+) IN HI Figure 6. Floating Input Measurements (9V-Powered Models) 12 (–) IN LO 7 REF IN 1 +5V SUP 3 5V RET 120 VAC AC to DC Converter Figure 4. Input Attenuation Circuit 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-20LCD 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: www.murata-ps.com/support MPM_DMS20LCD.C01 Page 4 of 6 DMS-20LCD Series 3½ Digit, LCD Display Digital Panel Voltmeters APPLICATIONS Therefore, the 9V battery voltage appears to the meter inputs as 0.9V. With the decimal point moved to its DP2 position (pin 5 tied to pin 3), the meter reads 9.00 Volts. RShunt = R1 = VFsr / I Fsr Where: VFsr = Full scale reading (in Volts) The circuit can be calibrated by first measuring the actual battery voltage with another meter and then adjusting the gain-adjust potentiometer on the back of the DMS-20LCD until a similar reading is obtained. If possible, the resistors in the divider should be ±1% metal-film types with TCR’s less than 50ppm/°C. I Fsr = Relative full scale current (in Amps) Example: For a meter with a 2V full scale input (1.999 full scale reading) and a desired full scale display reading of 1000 (with an input of 20mA), VFsr = 1.000 Volts RShunt = 1.000V/(0.020 – 0.004)A RShunt = 1.000V/0.016A = 62.5 Ohms DMS-20LCD-1-9 R1 45.3k 11 (+) IN HI REF OUT 8 To calibrate the circuit of Figure 7, perform the following: R2 10.1k 12 (–) IN LO 1. With 4mA applied, adjust the 50k potentiometer (R2) to display a reading of "000" (assuming that is the desired reading). REF IN 7 1 +BAT R3 45.3k 5 DP2 + 2. With 20mA applied, adjust the gain-adjust potentiometer on the back of the meter to display a reading of "1999". For different full scale readings, alter the value of RShunt accordingly. 3 –BAT 9V BATTERY – Figure 8. Power Supply Monitor (9V-Powered Models) 11 (+) IN HI DMS-20LCD-1-5 8 REF OUT 7. External Gain Adjustment: Connect REFERENCE OUT (pin 8) to REFERENCE IN (pin 7) for normal, factory calibrated, operation. Use the circuit shown in Figure 9 for applications needing external gain adjustment. Calibration is performed with a precise, near-full-scale, input voltage. + 10 ANA COMM 4-20mA R1 12 7 REF IN (–) IN LO 1 R2 +5V SUP 3 5V RET – 50k 11 (+) IN HI DMS-20LCD OUT 120 VAC AC to DC Converter Figure 7. 4-to-20mA Current Loop Operation (5V-Powered Models) 12 VOLTAGE CALIBRATOR COM 3 5V RET/ –BAT IN 12 Connections for ±2V, ±20V and ±200V models (–) IN LO 10 ANA COMM 6. Power Supply Monitoring: A popular application for Murata Power Solutions’ low-power LCD meters is monitoring the supply voltage in battery-operated portable equipment. Figure 8 demonstrates how a 9V-powered DMS-20LCD can be used to monitor its own supply. The meter used is the DMS-20LCD-1-9. A three-resistor voltage divider is used to attenuate the battery voltage and also to satisfy the requirement that the input voltages applied to pins 12 and 11 be at least 1.5 Volts above and below the battery voltage applied to pins 1 (+BATTERY) and 3 (–BATTERY). The divider should be designed so that 1/10th the battery voltage falls across the inputs to the meter: 1 +5V IN/ +BAT IN 8 NC 8.06k, 1% 7 REF IN 2k 17.4k, 1% For +5V models, tie (–) IN LO to pin 3. For +9V models, tie (–) IN LO to pin 10 732, 1% 200 24.3k, 1% Connections for ±200mV models = 10 to 20 Turns Figure 9. External Gain Adjustment R2 = 0.1 (R1 + R2 + R3) www.murata-ps.com/support MPM_DMS20LCD.C01 Page 5 of 6 DMS-20LCD Series 3½ Digit, LCD Display Digital Panel Voltmeters MECHANICAL SPECIFICATIONS MECHANICAL DIMENSIONS: Inches (mm) TOLERANCES: 2 PL DEC ±0.02 (±0.51) 3 PL DEC ±0.010 (±0.254) PIN #1 IDENTIFIER DMS-20LCD-X-XX 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) CALIBRATION POTENTIOMETER HOLE LOCATION PIN 1 0.160 (4.06) FRONT VIEW +5V SUPPLY/ +BATTERY N.C. 5V RETURN/ –BATTERY DP3 DP2 DP1 12 11 10 9 8 7 1 2 3 4 5 6 0.160 (4.06) DP1 0.125 (3.175) DIAMETER (USE ONLY WHEN PC BOARD MOUNTING) DP2 0.88 (22.3) 1.38 (35.1) 0.80 (20.3) 1.30 (33.0) (–) INPUT LO (+) INPUT HI ANALOG COMMON N.C./BACKLIGHT REFERENCE OUT REFERENCE IN DP3 0.425 (10.80) 0.040 (1.02) 0.040 (1.02) 0.10 (2.5) TYP. 0.15 (3.8) TYP. 0.25 (6.4) TYP. 0.10 (2.5) TYP. 1.10 (27.9) 0.040 (1.02) 0.50 (12.7) BEZEL INSTALLATION AND RECOMMENDED DRILL AND PANEL CUTOUT OPTIONAL BEZEL (DMS BZL3 and DMS BZL4) #2-56 INSERT 0.156 (3.96) DEEP BEZEL INSTALLATION 0.187 (4.75) FRONT VIEW PANEL 1.280 (32.51) 1.826 (46.38) BEZEL RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS INTERNAL CORNER RADII: 0.032 (0.81) MAX. RETAINING CLIP INSTALLATION 1.07 (27.18) 0.838 (21.29) 1.336 (33.93) 1.626 (41.30) 0.093 (2.362) DIAMETER (4 REQUIRED) ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY 0.145 (3.68) PANEL 0.116 (2.95) Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, 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/ 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. Specifications are subject to change without notice. © 2015 Murata Power Solutions, Inc. www.murata-ps.com/support MPM_DMS20LCD.C01 Page 6 of 6