LM20 NSC | Alldatasheet
Document overview
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Technical content
Features
n Rated for full −55˚C to +130˚C range n Available in an SC70 and a micro SMD package n Predictable curvature error n Suitable for remote applications Key Specifications n Accuracy at +30˚C ±1.5 to±4 ˚C (max) n Accuracy at +130˚C & −55˚C ±2.5 to±5 ˚C (max) n Power Supply Voltage Range +2.4V to +5.5V n Current Drain 10 µA (max) n Nonlinearity ±0.4% (typ) n Output Impedance 160 Ω (max) n Load Regulation 0µ A < IL< +16 µA −2.5 mV (max) Typical Application DS100908-2 or where: T is temperature, and VO is the measured output voltage of the LM20. Output Voltage vs Temperature DS100908-24 Full-Range Celsius (Centigrade) Temperature Sensor (−55˚C to +130˚C) Operating from a Single Li-Ion Battery Cell October 1999 LM20 2.4V, 10µA, SC70, micro SMD Temperature Sensor © 1999 National Semiconductor Corporation DS100908 www.national.com
Typical Application(Continued) Temperature (T) Typical V O +130˚C +303 mV +100˚C +675 mV +80˚C +919 mV +30˚C +1515 mV Temperature (T) Typical V O +25˚C +1574 mV 0˚C +1863.9 mV −30˚C +2205 mV −40˚C +2318 mV −55˚C +2485 mV Connection Diagrams
Ordering Information
Order Temperature Temperature NS Package Device Number Accuracy Range Number Marking Transport Media LM20BIM7 ±2.5˚C −55˚C to +130˚C MAA05A T2B 1000 Units on Tape and Reel LM20BIM7X ±2.5˚C −55˚C to +130˚C MAA05A T2B 3000 Units on Tape and Reel LM20CIM7 ±5˚C −55˚C to +130˚C MAA05A T2C 1000 Units on Tape and Reel LM20CIM7X ±5˚C −55˚C to +130˚C MAA05A T2C 3000 Units on Tape and Reel LM20SIBP ±3.5˚C −40˚C to +125˚C BPA04DDC Date Code
250 Units on Tape and Reel
LM20SIBPX ±3.5˚C −40˚C to +125˚C BPA04DDC Date Code
3000 Units on Tape and Reel
Note: - GND (pin 2) may be grounded or left floating. For optimum thermal conductivity to the pc board ground plane pin 2 should be grounded. - NC (pin 1) should be left floating or grounded. Other signal traces should not be connected to this pin. Top View See NS Package Number MAA05A micro SMD DS100908-32 Note: - Pin numbers are referenced to the package marking text orientation. - Reference JEDEC Registration MO-211, variation BA - The actual physical placement of package marking will vary slightly from part to part. The package marking will designate the date code and will vary considerably. Package marking does not correlate to device type in any way. Top View See NS Package Number BPA04DDC LM20 www.national.com 2
Absolute Maximum Ratings(Note 1) Supply Voltage +6.5V to −0.2V Output Voltage (V + + 0.6 V) to −0.6 V Output Current 10 mA Input Current at any pin (Note 2) 5 mA Storage Temperature −65˚C to +150˚C Maximum Junction Temperature (T JMAX ) +150˚C ESD Susceptibility (Note 3) : Human Body Model 2500 V Machine Model 250 V Lead Temperature Vapor Phase (60 seconds) +215˚C Infrared (15 seconds) +220˚C Operating Ratings(Note 1) Specified Temperature Range: TMIN ≤ TA ≤ TMAX LM20B, LM20C with LM20B, LM20C with LM20S with LM20S with Supply Voltage Range (V+) +2.4 V to +5.5 V Thermal Resistance,θJA(Note 5) SC-70 micro SMD 415˚C/W TBD˚C/W
Electrical Characteristics
Unless otherwise noted, these specifications apply for V+ = +2.7 VDC .Boldface limits apply for TA = TJ = TMIN to TMAX ; all other limits TA = TJ = 25˚C; Unless otherwise noted. Parameter Conditions Typical (Note 6) LM20B LM20C LM20S Units (Limit)Limits Limits Limits (Note 7) (Note 7) (Note 7) Temperature to Voltage Error VO = (−3.88x10−6xT2) (Note 8) Output Voltage at 0˚C +1.8639 V Variance from Curve ±1.0 ˚C Non-Linearity (Note 9) −20˚C ≤ TA ≤ +80˚C ±0.4 % Sensor Gain (Temperature Sensitivity or Average Slope) to equation: V O =−11.77 mV/˚CxT+1.860V −12.2 −11.0 −12.6 −11.0 −12.6 mV/˚C (min) mV/˚C (max) Output Impedance 0 µA ≤ IL ≤ +16 µA(Notes 11, 12) 160 160 160 Ω (max) Load Regulation(Note 10) 0 µA ≤ IL ≤ +16 µA(Notes 11, 12) Quiescent Current +2. 4 V ≤ V+ ≤ +5.5V 4.5 7 7 7 µA (max) + 2 .4V≤ V+ ≤ +5.0V 4.5 10 10 10 µA (max) Change of Quiescent Current +2. 4 V≤ V+ ≤ +5.5V +0.7 µA Temperature Coefficient of −11 nA/˚C Quiescent Current Shutdown Current V + ≤ +0.8 V 0.02 µA LM20 www.national.com3
fications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. Note 2:When the input voltage (VI) at any pin exceeds power supplies (VI < GND or VI > V+), the current at that pin should be limited to 5 mA. conductor Linear Data Book for other methods of soldering surface mount devices. Note 6:Typicals are at TJ = TA = 25˚C and represent most likely parametric norm. Note 7:Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). puted by multiplying the internal dissipation by the thermal resistance. Note 12:Load regulation or output impedance specifications apply over the supply voltage range of +2.4V to +5.5V. Note 13:Line regulation is calculated by subtracting the output voltage at the highest supply input voltage from the output voltage at the lowest supply inputvoltage. a) Layout used for no heat sink measurements. b) Layout used for measurements with small heat hink. FIGURE 1. PCB Lyouts used for thermal measurements.
1.0 LM20 Transfer Function
- VOP (Tmax ) is the calculated output voltage at Tmax using the parabolic transfer function for VO
- VOP (T) is the calculated output voltage at T using the parabolic transfer function for VO . Using this procedure the best fit linear transfer function for many popular temperature ranges was calculated inFigure 2. As shown inFigure 2the error that is introduced by the lin- ear transfer function increases with wider temperature ranges.
2.0 Mounting
which the LM20’s leads are attached to. LM20 will also affect the temperature that is being sensed. minimize the load current that the LM20 is required to drive. resistance for different conditions. FIGURE 2. First order equations optimized for different temperature ranges.
Figure 4. Over the specified temperature range the LM20 has a maximum output impedance of 160Ω .
- A 1 µF output capacitor with the 160Ω maximum output
4.0 LM20 micro SMD Light Sensitivity
output voltage to recover to the proper value. Figure 1for PCB layout samples. FIGURE 3. Temperature Rise of LM20 Due to FIGURE 4. LM20 No Decoupling Required for Capacitive Loads Less than 300 pF. FIGURE 5. LM20 with Filter for Noisy Environment and Capacitive Loading greater than 300 pF. Either placement of resistor as shown above is just as effective.
5.0 Applications Circuits
FIGURE 6. Centigrade Thermostat FIGURE 7. Conserving Power Dissipation with Shutdown is shown as an example only. If a digital output temperature is required please refer to devices such as the LM74. FIGURE 8. Suggested Connection to a Sampling Analog to Digital Converter Input Stage
Physical Dimensionsinches (millimeters) unless otherwise noted 5-Lead SC70 Molded Package Order Number LM20BIM7 or LM20CIM7X LM20 www.national.com 8
Physical Dimensionsinches (millimeters) unless otherwise noted (Continued) LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: sea.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 www.national.com 4-Bump micro SMD Ball Grid Array Package Order Number LM20SIBP or LM20SIBPX The following dimensions apply to the BPA04DDC package shown above: X1=X2 = 853µm ±30µm, X3= 900µm ±50µm LM20 2.4V, 10µA, SC70, micro SMD Temperature Sensor National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.