LMT87DCKR

Order Now Product Folder Support & Community Tools & Software Technical Documents LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 LMT87 2.7-V, SC70/TO-92/TO-92S, Analog Temperature Sensors With Class-AB Output 1 Features 3 Description • The LMT87 device is a precision CMOS temperature sensor with ±0.4°C typical accuracy (±2.7°C maximum) and a linear analog output voltage that is inversely proportional to temperature. The 2.7-V supply voltage operation, 5.4-μA quiescent current, and 0.7-ms power-on time enable effective powercycling architectures to minimize power consumption for battery-powered applications such as drones and sensor nodes. The LMT87LPG through-hole TO-92S package fast thermal time constant supports offboard time-temperature sensitive applications such as smoke and heat detectors. The accuracy over the wide operating range and other features make the LMT87 an excellent alternative to thermistors. 1 • • • • • • • • • LMT87LPG (TO-92S package) has a Fast Thermal Time Constant, 10-s Typical (1.2 m/s Airflow) Very Accurate: ±0.4°C Typical Low 2.7-V Operation Average Sensor Gain of -13.6 mV/°C Low 5.4-µA Quiescent Current Wide Temperature Range: –50°C to 150°C Output is Short-Circuit Protected Push-Pull Output With ±50-µA Drive Capability Footprint Compatible With the Industry-Standard LM20/19 and LM35 Temperature Sensors Cost-Effective Alternative to Thermistors 2 Applications • • • • • • Automotive Infotainment and Cluster Powertrain Systems Smoke and Heat Detectors Drones Appliances For devices with different average sensor gains and comparable accuracy, refer to Comparable Alternative Devices for alternative devices in the LMT8x family. Device Information (1) PART NUMBER LMT87 (1) PACKAGE BODY SIZE (NOM) SOT (5) 2.00 mm × 1.25 mm TO-92 (3) 4.30 mm × 3.50 mm TO-92S (3) 4.00 mm × 3.15 mm For all available packages, see the orderable addendum addendum at the end of the data sheet. Thermal Time Constant Output Voltage vs Temperature VDD (+2.7V to +5.5V) 100% FINAL TEMPERATURE 90% 80% VDD 70% 60% LMT87 50% CBP OUT 40% 30% 20% GND LMT8xLPG Thermistor 10% 0 0 20 40 60 TIME (s) 80 100 D003 Copyright © 2016, Texas Instruments Incorporated * Fast thermal response NTC 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com Table of Contents 1 2 3 4 5 6 7 8 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Device Comparison Tables................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 5 7.1 7.2 7.3 7.4 7.5 7.6 7.7 5 5 5 5 6 6 7 Absolute Maximum Ratings ...................................... ESD Ratings.............................................................. Recommended Operating Conditions....................... Thermal Information .................................................. Accuracy Characteristics........................................... Electrical Characteristics .......................................... Typical Characteristics ............................................. Detailed Description .............................................. 9 8.1 Overview ................................................................... 9 8.2 Functional Block Diagram ......................................... 9 8.3 Feature Description................................................... 9 8.4 Device Functional Modes........................................ 11 9 Application and Implementation ........................ 13 9.1 Application Information............................................ 13 9.2 Typical Applications ............................................... 13 10 Power Supply Recommendations ..................... 14 11 Layout................................................................... 15 11.1 Layout Guidelines ................................................. 15 11.2 Layout Example .................................................... 15 12 Device and Documentation Support ................. 16 12.1 12.2 12.3 12.4 12.5 Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 16 16 16 16 16 13 Mechanical, Packaging, and Orderable Information ........................................................... 16 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision D (June 2017) to Revision E Page • Moved the automotive device to a standalone data sheet (SNIS202) .................................................................................. 1 • Changed TO-92 GND pin number from: 1 to: 3 .................................................................................................................... 4 • Changed TO-92 VDD pin number from: 3 to: 1 ...................................................................................................................... 4 Changes from Revision C (October 2015) to Revision D Page • Updated data sheet text to the latest documentation and translations standards ................................................................. 1 • Added AEC-Q100 automotive qualification bullets to Features ............................................................................................. 1 • Added Time Constant graph................................................................................................................................................... 1 • Removed disk drivers, games, wireless transceivers, and cell phones from Applications..................................................... 1 • Added LPG (TO-92S) package .............................................................................................................................................. 4 • Added Figure 10 to Typical Characteristics............................................................................................................................ 7 Changes from Revision B (May 2014) to Revision C Page • Deleted all mentions of TO-126 package .............................................................................................................................. 1 • Added TO-92 LPM pin configuration graphic ......................................................................................................................... 4 • Changed Handling Ratings to ESD Ratings and moved Storage Temperature to Absolute Maximum Ratings table........... 5 • Changed KV to V ................................................................................................................................................................... 5 • Added layout recommendation for TO-92 LP and LPM packages....................................................................................... 15 Changes from Revision A (June 2013) to Revision B Page • Added data sheet flow and layout to conform with new TI standards. Added the following sections: Application and Implementation, Power Supply Recommendations, Layout, Device and Documentation Support, Mechanical, Packaging, and Orderable Information .................................................................................................................................. 1 • Added TO-92 and TO-126 package information. .................................................................................................................. 1 2 Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 • Changed from 450°C/W to 275 °C/W. New specification is derived using TI ' s latest methodology. .................................. 5 • Deleted Note: The input current is leakage only and is highest at high temperature. It is typically only 0.001 μA. The 1 μA limit is solely based on a testing limitation and does not reflect the actual performance of the part............................. 6 5 Device Comparison Tables Table 1. Available Device Packages ORDER NUMBER (1) PACKAGE PIN BODY SIZE (NOM) MOUNTING TYPE LMT87DCK SOT (AKA (2): SC70, DCK) 5 2.00 mm × 1.25 mm Surface Mount LMT87LP TO-92 (AKA (2): LP) 3 4.30 mm × 3.50 mm Through-hole; straight leads (2) LMT87LPG TO-92S (AKA 3 4.00 mm × 3.15 mm Through-hole; straight leads LMT87LPM TO-92 (AKA (2): LPM) 3 4.30 mm × 3.50 mm Through-hole; formed leads LMT87DCK-Q1 SOT (AKA (2): SC70, DCK) 5 2.00 mm × 1.25 mm Surface Mount (1) (2) : LPG) For all available packages and complete order numbers, see the Package Option addendum at the end of the data sheet. AKA = Also Known As Table 2. Comparable Alternative Devices DEVICE NAME AVERAGE OUTPUT SENSOR GAIN POWER SUPPLY RANGE LMT84 –5.5 mV/°C 1.5 V to 5.5 V LMT85 –8.2 mV/°C 1.8 V to 5.5 V LMT86 –10.9 mV/°C 2.2 V to 5.5 V LMT87 –13.6 mV/°C 2.7 V to 5.5 V Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 3 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com 6 Pin Configuration and Functions DCK Package 5-Pin SOT (SC70) Top View 1 LP Package 3-Pin TO-92 (Top View) 5 VDD VDD 2 LMT87 GND 3 4 OUT VDD 1 D VD LPG Package 3-Pin TO-92S (Top View) G 3 D N 2 T U O 1 Scale: 4:1 2 3 LPM Package 3-Pin TO-92 (Top View) 1 T U O 3 D VD 2 D N G Scale: 4:1 1 D VD 2 T U O 3 D N G Scale: 4:1 Pin Functions PIN NAME GND SOT (SC70) TO-92 TO-92S 2 (1) 3 2 TYPE DESCRIPTION EQUIVALENT CIRCUIT Ground N/A FUNCTION Power Supply Ground VDD OUT 3 2 1 Analog Output VDD 1, 4, 5 1 3 Power Outputs a voltage that is inversely proportional to temperature GND (1) 4 N/A Positive Supply Voltage Direct connection to the back side of the die Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 7 Specifications 7.1 Absolute Maximum Ratings See (1) (2) MIN MAX UNIT Supply voltage –0.3 6 V Voltage at output pin –0.3 (VDD + 0.5) V Output current –7 7 mA Input current at any pin (3) –5 5 mA 150 °C 150 °C Maximum junction temperature (TJMAX) Storage temperature Tstg (1) (2) (3) –65 Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Soldering process must comply with Reflow Temperature Profile specifications. Refer to www.ti.com/packaging. 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. 7.2 ESD Ratings VALUE UNIT LMT87LP in TO-92 package V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) (2) ±2500 Charged-device model (CDM), per JEDEC specification JESD22-C101 (3) ±1000 Human-body model (HBM), per JESD22-A114 (2) ±2500 Charged-device model (CDM), per JEDEC specification JESD22-C101 (3) ±1000 V LMT87DCK in SC70 package V(ESD) (1) (2) (3) Electrostatic discharge V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. The human-body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each pin. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 7.3 Recommended Operating Conditions MIN Specified temperature MAX UNIT TMIN ≤ TA ≤ TMAX °C −50 ≤ TA ≤ 150 °C Supply voltage (VDD) 2.7 5.5 V 7.4 Thermal Information (1) THERMAL METRIC (2) (3) (4) LMT87 LMT87LP LMT87LPG DCK (SOT/SC70) LP/LPM (TO-92) LPG (TO-92S) 5 PINS 3 PINS 3 PINS UNIT RθJA Junction-to-ambient thermal resistance 275 167 130.4 °C/W RθJC(top) Junction-to-case (top) thermal resistance 84 90 64.2 °C/W RθJB Junction-to-board thermal resistance 56 146 106.2 °C/W ψJT Junction-to-top characterization parameter 1.2 35 14.6 °C/W ψJB Junction-to-board characterization parameter 55 146 106.2 °C/W (1) (2) (3) (4) For information on self-heating and thermal response time see section Mounting and Thermal Conductivity. For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report. The junction to ambient thermal resistance (RθJA) under natural convection is obtained in a simulation on a JEDEC-standard, High-K board as specified in JESD51-7, in an environment described in JESD51-2. Exposed pad packages assume that thermal vias are included in the PCB, per JESD 51-5. Changes in output due to self-heating can be computed by multiplying the internal dissipation by the thermal resistance. Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 5 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com 7.5 Accuracy Characteristics These limits do not include DC load regulation. These stated accuracy limits are with reference to the values in Table 3. PARAMETER CONDITIONS 70°C to 150°C; VDD = 3.0 V to 5.5 V MIN (1) TYP MAX (1) –2.7 ±0.4 2.7 20°C to 40°C; VDD = 2.7 V to 5.5 V ±0.6 20°C to 40°C; VDD = 3.4 V to 5.5 V ±0.3 Temperature accuracy (2) 0°C; VDD = 3.0 V to 5.5 V –2.7 0°C; VDD = 3.6 V to 5.5 V –2.7 –50°C; VDD = 4.2 V to 5.5 V (1) (2) °C °C °C ±0.6 2.7 ±0.3 –50°C; VDD = 3.6 V to 5.5 V UNIT °C °C ±0.6 2.7 ±0.3 °C °C Limits are specific to TI's AOQL (Average Outgoing Quality Level). Accuracy is defined as the error between the measured and reference output voltages, tabulated in the Transfer Table at the specified conditions of supply gain setting, voltage, and temperature (expressed in °C). Accuracy limits include line regulation within the specified conditions. Accuracy limits do not include load regulation; they assume no DC load. 7.6 Electrical Characteristics Unless otherwise noted, these specifications apply for +VDD = 2.7 V to 5.5 V. MIN and MAX limits apply for TA = TJ = TMIN to TMAX ; typical limits apply for TA = TJ = 25°C. PARAMETER TEST CONDITIONS MIN (1) Sensor gain (output transfer function slope) Load regulation (3) Supply current CL Output load capacitance (1) (2) (3) (4) (5) 6 (2) MAX (1) –13.6 Source ≤ 50 μA, (VDD – VOUT) ≥ 200 mV –1 Sink ≤ 50 μA, VOUT ≥ 200 mV mV 1 200 TA = 30°C to 150°C, (VDD – VOUT) ≥ 100 mV TA = –50°C to 150°C, (VDD – VOUT) ≥ 100 mV CL= 0 pF to 1100 pF Output drive TA = TJ = 25°C 5.4 8.1 μA 5.4 9 μA 1.9 ms 50 μA 0.7 –50 mV μV/V 1100 Power-on time (5) UNIT mV/°C –0.22 0.26 Line regulation (4) IS TYP pF Limits are specific to TI's AOQL (Average Outgoing Quality Level). Typicals are at TJ = TA = 25°C and represent most likely parametric norm. Source currents are flowing out of the LMT87. Sink currents are flowing into the LMT87. Line regulation (DC) is calculated by subtracting the output voltage at the highest supply voltage from the output voltage at the lowest supply voltage. The typical DC line regulation specification does not include the output voltage shift discussed in Output Voltage Shift. Specified by design and characterization. Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 7.7 Typical Characteristics 4 TEMPERATURE ERROR (ºC) 3 2 1 0 -1 -2 -3 -4 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (ºC) Figure 1. Temperature Error vs Temperature Figure 2. Minimum Operating Temperature vs Supply Voltage Figure 3. Supply Current vs Temperature Figure 4. Supply Current vs Supply Voltage Figure 5. Load Regulation, Sourcing Current Figure 6. Load Regulation, Sinking Current Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 7 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com Typical Characteristics (continued) Figure 7. Change in VOUT vs Overhead Voltage Figure 8. Supply-Noise Gain vs Frequency 100% FINAL TEMPERATURE 90% 80% 70% 60% 50% 40% 30% 20% LMT8xLPG Thermistor 10% 0 0 Figure 9. Output Voltage vs Supply Voltage 8 20 40 60 TIME (s) 80 100 D003 Figure 10. LMT87LPG Thermal Response vs Common Leaded Thermistor With 1.2-m/s Airflow Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 8 Detailed Description 8.1 Overview The LMT87 is an analog output temperature sensor. The temperature-sensing element is comprised of a simple base emitter junction that is forward biased by a current source. The temperature-sensing element is then buffered by an amplifier and provided to the OUT pin. The amplifier has a simple push-pull output stage thus providing a low impedance output source. 8.2 Functional Block Diagram Full-Range Celsius Temperature Sensor (−50°C to +150°C) VDD OUT Thermal Diodes GND 8.3 Feature Description 8.3.1 LMT87 Transfer Function The output voltage of the LMT87, across the complete operating temperature range, is shown in Table 3. This table is the reference from which the LMT87 accuracy specifications (listed in the Accuracy Characteristics section) are determined. This table can be used, for example, in a host processor look-up table. A file containing this data is available for download at the LMT87 product folder under Tools and Software Models. Table 3. LMT87 Transfer Table TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) –50 3277 –10 2767 30 2231 70 1679 110 1115 –49 3266 –9 2754 31 2217 71 1665 111 1101 –48 3254 –8 2740 32 2204 72 1651 112 1087 –47 3243 –7 2727 33 2190 73 1637 113 1073 –46 3232 –6 2714 34 2176 74 1623 114 1058 –45 3221 –5 2700 35 2163 75 1609 115 1044 –44 3210 –4 2687 36 2149 76 1595 116 1030 –43 3199 –3 2674 37 2136 77 1581 117 1015 –42 3186 –2 2660 38 2122 78 1567 118 1001 –41 3173 –1 2647 39 2108 79 1553 119 987 –40 3160 0 2633 40 2095 80 1539 120 973 –39 3147 1 2620 41 2081 81 1525 121 958 –38 3134 2 2607 42 2067 82 1511 122 944 Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 9 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com Feature Description (continued) Table 3. LMT87 Transfer Table (continued) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) TEMP (°C) VOUT (mV) –37 3121 3 2593 43 2054 83 1497 123 929 –36 3108 4 2580 44 2040 84 1483 124 915 –35 3095 5 2567 45 2026 85 1469 125 901 –34 3082 6 2553 46 2012 86 1455 126 886 –33 3069 7 2540 47 1999 87 1441 127 872 –32 3056 8 2527 48 1985 88 1427 128 858 –31 3043 9 2513 49 1971 89 1413 129 843 –30 3030 10 2500 50 1958 90 1399 130 829 –29 3017 11 2486 51 1944 91 1385 131 814 –28 3004 12 2473 52 1930 92 1371 132 800 –27 2991 13 2459 53 1916 93 1356 133 786 –26 2978 14 2446 54 1902 94 1342 134 771 –25 2965 15 2433 55 1888 95 1328 135 757 –24 2952 16 2419 56 1875 96 1314 136 742 –23 2938 17 2406 57 1861 97 1300 137 728 –22 2925 18 2392 58 1847 98 1286 138 713 –21 2912 19 2379 59 1833 99 1272 139 699 –20 2899 20 2365 60 1819 100 1257 140 684 –19 2886 21 2352 61 1805 101 1243 141 670 –18 2873 22 2338 62 1791 102 1229 142 655 –17 2859 23 2325 63 1777 103 1215 143 640 –16 2846 24 2311 64 1763 104 1201 144 626 –15 2833 25 2298 65 1749 105 1186 145 611 –14 2820 26 2285 66 1735 106 1172 146 597 –13 2807 27 2271 67 1721 107 1158 147 582 –12 2793 28 2258 68 1707 108 1144 148 568 –11 2780 29 2244 69 1693 109 1130 149 553 150 538 Although the LMT87 is very linear, the response does have a slight umbrella parabolic shape. This shape is very accurately reflected in Table 3. The transfer table can be calculated by using the parabolic equation (Equation 1). mV mV ª º ª VTEMP mV = 2230.8mV - «13.582 T - 30°C » - «0.00433 2 T - 30°C °C ¬ ¼ ¬ °C 2º » ¼ (1) The parabolic equation is an approximation of the transfer table and the accuracy of the equation degrades slightly at the temperature range extremes. Equation 1 can be solved for T resulting in: T 13 .582 13 .582 2 4 u 0.00433 u 2230 .8 VTEMP mV 2 u ( 0.00433 ) 30 (2) For an even less accurate linear transfer function approximation, a line can easily be calculated over the desired temperature range from Table 3 using the two-point equation (Equation 3): · ¹ V - V1 = V2 - V1 T2 - T1 · u (T - T1) ¹ where • • • • 10 V is in mV, T is in °C, T1 and V1 are the coordinates of the lowest temperature, and T2 and V2 are the coordinates of the highest temperature. Submit Documentation Feedback (3) Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 For example, if the user wanted to resolve this equation, over a temperature range of 20°C to 50°C, they would proceed as follows: 1958 mV - 2365 mV· u (T - 20oC) 50oC - 20oC ¹ · ¹ V - 2365 mV = (4) o o V - 2365 mV = (-13.6 mV / C) u (T - 20 C) (5) o V = (-13.6 mV / C) u T + 2637 mV (6) Using this method of linear approximation, the transfer function can be approximated for one or more temperature ranges of interest. 8.4 Device Functional Modes 8.4.1 Mounting and Thermal Conductivity The LMT87 can be applied easily in the same way as other integrated-circuit temperature sensors. It can be glued or cemented to a surface. To ensure good thermal conductivity, the backside of the LMT87 die is directly attached to the GND pin. The temperatures of the lands and traces to the other leads of the LMT87 will also affect the temperature reading. Alternatively, the LMT87 can be mounted inside a sealed-end metal tube, and can then be dipped into a bath or screwed into a threaded hole in a tank. As with any IC, the LMT87 and accompanying wiring and circuits must be kept insulated and dry, to avoid leakage and corrosion. This is especially true if the circuit may operate at cold temperatures where condensation can occur. If moisture creates a short circuit from the output to ground or VDD, the output from the LMT87 will not be correct. Printed-circuit coatings are often used to ensure that moisture cannot corrode the leads or circuit traces. The thermal resistance junction to ambient (RθJA or θJA) is the parameter used to calculate the rise of a device junction temperature due to its power dissipation. Use Equation 7 to calculate the rise in the LMT87 die temperature: TJ = TA + TJA ª¬(VDDIS ) + (VDD - VOUT ) IL º¼ where • • • • TA is the ambient temperature, IS is the supply current, ILis the load current on the output, and VO is the output voltage. (7) For example, in an application where TA = 30°C, VDD = 5 V, IS = 5.4 μA, VOUT = 2231 mV, and IL = 2 μA, the junction temperature would be 30.014°C, showing a self-heating error of only 0.014°C. Because the junction temperature of the LMT87 is the actual temperature being measured, take care to minimize the load current that the LMT87 is required to drive. Thermal Information (1) shows the thermal resistance of the LMT87. 8.4.2 Output Noise Considerations A push-pull output gives the LMT87 the ability to sink and source significant current. This is beneficial when, for example, driving dynamic loads like an input stage on an analog-to-digital converter (ADC). In these applications the source current is required to quickly charge the input capacitor of the ADC. The LMT87 is ideal for this and other applications which require strong source or sink current. The LMT87 supply-noise gain (the ratio of the AC signal on VOUT to the AC signal on VDD) was measured during bench tests. The typical attenuation is shown in Figure 8 found in the Typical Characteristics section. A load capacitor on the output can help to filter noise. For operation in very noisy environments, some bypass capacitance should be present on the supply within approximately 5 centimeters of the LMT87. (1) For information on self-heating and thermal response time see section Mounting and Thermal Conductivity. Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 11 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com Device Functional Modes (continued) 8.4.3 Capacitive Loads The LMT87 handles capacitive loading well. In an extremely noisy environment, or when driving a switched sampling input on an ADC, it may be necessary to add some filtering to minimize noise coupling. Without any precautions, the LMT87 can drive a capacitive load less than or equal to 1100 pF, as shown in Figure 11. For capacitive loads greater than 1100 pF, a series resistor may be required on the output, as shown in Figure 12. VDD LMT87 OPTIONAL BYPASS CAPACITANCE OUT GND CLOAD ” 1100 pF Figure 11. LMT87 No Decoupling Required for Capacitive Loads Less Than 1100 pF VDD RS LMT87 OUT OPTIONAL BYPASS CAPACITANCE GND CLOAD > 1100 pF Figure 12. LMT87 with Series Resistor for Capacitive Loading Greater Than 1100 pF Table 4. Recommended Series Resistor Values CLOAD MINIMUM RS 1.1 nF to 99 nF 3 kΩ 100 nF to 999 nF 1.5 kΩ 1 μF 800 Ω 8.4.4 Output Voltage Shift The LMT87 is very linear over temperature and supply voltage range. Due to the intrinsic behavior of an NMOS/PMOS rail-to-rail buffer, a slight shift in the output can occur when the supply voltage is ramped over the operating range of the device. The location of the shift is determined by the relative levels of VDD and VOUT. The shift typically occurs when VDD- VOUT = 1 V. This slight shift (a few millivolts) takes place over a wide change (approximately 200 mV) in VDD or VOUT. Because the shift takes place over a wide temperature change of 5°C to 20°C, VOUT is always monotonic. The accuracy specifications in the Accuracy Characteristics table already include this possible shift. 12 Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 9 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 9.1 Application Information The LMT87 features make it suitable for many general temperature-sensing applications. It can operate down to 2.7-V supply with 5.4-µA power consumption. Package options like the through-hole TO-92 package also allow the LMT87 to be mounted onboard, off-board, to a heat sink, or on multiple unique locations in the same application. 9.2 Typical Applications 9.2.1 Connection to ADC Simplified Input Circuit of SAR Analog-to-Digital Converter +2.7V to +5.5V Reset Input Pin LMT87 VDD CBP RMUX RSS Sample OUT GND CMUX CFILTER CSAMPLE Figure 13. Suggested Connection to a Sampling Analog-to-Digital Converter Input Stage 9.2.1.1 Design Requirements Most CMOS ADCs found in microcontrollers and ASICs have a sampled data comparator input structure. When the ADC charges the sampling cap, it requires instantaneous charge from the output of the analog source such as the LMT87 temperature sensor and many op amps. This requirement is easily accommodated by the addition of a capacitor (CFILTER). 9.2.1.2 Detailed Design Procedure The size of CFILTER depends on the size of the sampling capacitor and the sampling frequency. Because not all ADCs have identical input stages, the charge requirements will vary. This general ADC application is shown as an example only. 9.2.1.3 Application Curve 3.5 OUTPUT VOLTAGE (V) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 ±50 0 50 100 150 TEMPERATURE (ƒC) C001 Figure 14. Analog Output Transfer Function Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 13 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com Typical Applications (continued) 9.2.2 Conserving Power Dissipation With Shutdown VDD SHUTDOWN VOUT LMT87 Any logic device output Figure 15. Simple Shutdown Connection of the LMT87 9.2.2.1 Design Requirements Because the power consumption of the LMT87 is less than 9 µA, it can simply be powered directly from any logic gate output and therefore not require a specific shutdown pin. The device can even be powered directly from a microcontroller GPIO. In this way, it can easily be turned off for cases such as battery-powered systems where power savings are critical. 9.2.2.2 Detailed Design Procedure Simply connect the VDD pin of the LMT87 directly to the logic shutdown signal from a microcontroller. 9.2.2.3 Application Curves Time: 500 μs/div; Top trace: VDD 1 V/div; Bottom trace: OUT 1 V/div Figure 16. Output Turnon Response Time Without a Capacitive Load and VDD = 3.3 V Time: 500 μs/div; Top trace: VDD 1 V/div; Bottom trace: OUT 1 V/div Figure 17. Output Turnon Response Time With a 1.1-nF Capacitive Load and VDD = 3.3 V Time: 500 μs/div; Top trace: VDD 2 V/div; Bottom trace: OUT 1 V/div Figure 18. Output Turnon Response Time Without a Capacitive Load and VDD = 5 V Time: 500 μs/div; Top trace: VDD 2 V/div; Bottom trace: OUT 1 V/div Figure 19. Output Turnon Response Time With a 1.1-nF Capacitive Load and VDD = 5 V 10 Power Supply Recommendations The low supply current and supply range (2.7 V to 5.5 V) of the LMT87 allow the device to easily be powered from many sources. Power supply bypassing is optional and is mainly dependent on the noise on the power supply used. In noisy systems it may be necessary to add bypass capacitors to lower the noise that is coupled to the output of the LMT87. 14 Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 LMT87 www.ti.com SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 11 Layout 11.1 Layout Guidelines The LMT87 is extremely simple to layout. If a power-supply bypass capacitor is used, it should be connected as shown in the Layout Example. 11.2 Layout Example VIA to ground plane VIA to power plane VDD VDD VDD GND 0.01 µ F OUT VDD Figure 20. SC70 Package Recommended Layout GND OUT VDD Figure 21. TO-92 LP Package Recommended Layout GND OUT VDD Figure 22. TO-92 LPM Package Recommended Layout Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 15 LMT87 SNIS170E – JANUARY 2014 – REVISED OCTOBER 2017 www.ti.com 12 Device and Documentation Support 12.1 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 12.2 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 12.3 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 12.4 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 12.5 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 13 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. 16 Submit Documentation Feedback Copyright © 2014–2017, Texas Instruments Incorporated Product Folder Links: LMT87 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LMT87DCKR ACTIVE SC70 DCK 5 3000 RoHS & Green SN Level-1-260C-UNLIM -50 to 150 BUA LMT87DCKT ACTIVE SC70 DCK 5 250 RoHS & Green SN Level-1-260C-UNLIM -50 to 150 BUA LMT87LP ACTIVE TO-92 LP 3 1800 RoHS & Green SN N / A for Pkg Type -50 to 150 LMT87 LMT87LPG ACTIVE TO-92 LPG 3 1000 RoHS & Green SN N / A for Pkg Type -50 to 150 LMT87 LMT87LPGM ACTIVE TO-92 LPG 3 3000 RoHS & Green SN N / A for Pkg Type -50 to 150 LMT87 LMT87LPM ACTIVE TO-92 LP 3 2000 RoHS & Green SN N / A for Pkg Type -50 to 150 LMT87 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of