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LMT01QLPGQ1

LMT01QLPGQ1

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    TO226-2

  • 描述:

    2PINTEMPSENSORW/PULSEDCURR

  • 数据手册
  • 价格&库存
LMT01QLPGQ1 数据手册
Order Now Product Folder Technical Documents Support & Community Tools & Software LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 LMT01-Q1 0.5°C Accurate 2-Pin Digital Output Temperature Sensor With Pulse Count Interface 1 Features 3 Description • The LMT01-Q1 device is a high-accuracy, 2-pin temperature sensor with an easy-to-use pulse count current loop interface, which makes it suitable for onboard and offboard applications in automotive, industrial, and consumer markets. The LMT01-Q1 digital pulse count output and high accuracy over a wide temperature range allow pairing with any MCU without concern for integrated ADC quality or availability, while minimizing software overhead. TI’s LMT01-Q1 device achieves a maximum ±0.5°C accuracy with very fine resolution (0.0625°C) over a temperature range of –20°C to 90°C without system calibration or hardware and software compensation. 1 • • • • • • • • AEC-Q100 Qualified With the Following Results: – Temperature Grade 0 (E): –40°C to +150°C (2) – Temperature Grade 1 (Q): –40°C to +125°C – HBM ESD Component Classification Level 2 – CDM ESD Component Classification Level C5 High Accuracy Over –40°C to 150°C Wide Temperature Range – –20°C to 90°C: ±0.5°C (Maximum) – 90°C to 120°C: ±0.625°C (Maximum) – –40°C to –20°C: ±0.625°C (Maximum) Precision Digital Temperature Measurement Simplified in a 2-Pin Package Pulse Count Current Loop Easily Read by Processor. Pulse Count Proportional to Temperature With 0.0625°C Resolution Communication Frequency: 88 kHz Conversion Current: 34 µA Continuous Temperature Update Every 100 ms Floating 2-V to 5.5-V (VP–VN) Supply Operation With Integrated EMI Immunity Multiple 2-Pin Package Offerings: TO-92/LPG (3.1 mm × 4 mm × 1.5 mm) – ½ the Size of Traditional TO-92 and WSON With Wettable Flanks The LMT01-Q1’s pulse count interface is designed to directly interface with a GPIO or comparator input, thereby simplifying hardware implementation. Similarly, the LMT01-Q1's integrated EMI suppression and simple 2-pin architecture makes it suitable for onboard and offboard temperature sensing in a noisy environment. The LMT01-Q1 device can be easily converted into a two-wire temperature probe with a wire length up to two meters. Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) LMT01QLPG TO-92 (2) 4.00 mm × 3.15 mm LMT01ELPG TO-92 (2) 4.00 mm × 3.15 mm 2 Applications LMT01QDQX WSON (2) 1.70 mm × 2.50 mm • (1) For all available packages, see the orderable addendum at the end of the data sheet. (2) Applicable only for the LPG package. • • • Automotive – Battery Management Systems – Engine Management and ADAS Digital Output Wired Probes HVAC Power Supplies and Battery Management 2-Pin IC Temperature Sensor VDD: 3.0V to 5.5V GPIO Up to 2m VP LMT01-Q1 Accuracy Min 2.0V LMT01 MCU/ FPGA/ ASIC 1.0 VN Temperature Accuracy (ƒC) 0.8 Max Limit GPIO/ COMP 0.6 0.4 LMT01 Pulse Count Interface 0.2 Conversion Time ADC Conversion Result 0.0 Power Off -0.2 Power On -0.4 -0.6 Min Limit -0.8 -1.0 ±50 ±25 0 25 50 75 100 LMT01 Junction Temperaure (ƒC) 125 150 C014 Typical units plotted in center of curve. 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. LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com Table of Contents 1 2 3 4 5 6 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications......................................................... 1 1 1 2 3 4 6.1 6.2 6.3 6.4 6.5 6.6 Absolute Maximum Ratings ...................................... 4 ESD Ratings.............................................................. 4 Recommended Operating Conditions ...................... 4 Thermal Information .................................................. 4 Electrical Characteristics........................................... 5 Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT................................................... 6 6.7 Electrical Characteristics - WSON/DQX Pulse Count to Temperature LUT................................................... 6 6.8 Switching Characteristics .......................................... 7 6.9 Timing Diagram......................................................... 7 6.10 Typical Characteristics ............................................ 8 7 Detailed Description ............................................ 11 7.2 Functional Block Diagram ....................................... 11 7.3 Feature Description................................................. 11 7.4 Device Functional Modes........................................ 14 8 Application and Implementation ........................ 15 8.1 Application Information............................................ 15 8.2 Typical Application .................................................. 16 8.3 System Examples .................................................. 18 9 Power Supply Recommendations...................... 20 10 Layout................................................................... 21 10.1 Layout Guidelines ................................................. 21 10.2 Layout Example .................................................... 21 11 Device and Documentation Support ................. 22 11.1 11.2 11.3 11.4 11.5 Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 22 22 22 22 22 12 Mechanical, Packaging, and Orderable Information ........................................................... 22 7.1 Overview ................................................................. 11 4 Revision History Changes from Revision B (June 2017) to Revision C Page • Added device stamp to the TO-92 pinout top view ................................................................................................................ 3 • Changed the TO-92S pin numbers in the Pin Functions........................................................................................................ 3 Changes from Revision A (April 2017) to Revision B Page • Removed Electrical Characteristics: WSON/DQX table; Combined the LPG and DQX Electrical Characteristics tables together ........................................................................................................................................................................ 5 • Changed IOL maximum value from: 39 µA to: 40 µA .............................................................................................................. 5 • Changed leakage value from: 1 µA to 3.5 µA ........................................................................................................................ 5 • Moved the thermal response time parameters to the Electrical Characteristics table ........................................................... 5 • Added Missing Cross References ........................................................................................................................................ 11 Changes from Original (November 2016) to Revision A Page • Added new WSON/DQX package throughout data sheet ..................................................................................................... 1 • Changed updated package information. ................................................................................................................................ 3 • Added Electrical Characteristics - WSON/DQX Pulse Count to Temperature LUT ............................................................... 6 • Added -40 for Sample Calculations Table ........................................................................................................................... 12 • Added missing cross reference ........................................................................................................................................... 13 2 Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 5 Pin Configuration and Functions DQX Package 2-Pin WSON Bottom View VP VN LPG Package 2-Pin TO-92 Top View LM YM LL F T0 1 VN VP Pin Functions PIN NAME TO-92S WSON VP 2 1 VN 1 2 TYPE Input DESCRIPTION Positive voltage pin; may be connected to system power supply or bias resistor. Output Negative voltage pin; may be connected to system ground or a bias resistor. Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 3 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com 6 Specifications 6.1 Absolute Maximum Ratings (1) (2) See . MIN MAX UNIT Voltage drop (VP – VN) −0.3 6 V Storage temperature, Tstg −65 175 °C (1) (2) 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. 6.2 ESD Ratings VALUE V(ESD) (1) Electrostatic discharge Human-body model (HBM), per AEC Q100-002 (1) ±2000 Charged-device model (CDM), per AEC Q100-011 ±750 UNIT V AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification. 6.3 Recommended Operating Conditions MIN MAX UNIT Free-air temperature(LPG) -40 150 °C Free-air temperature (DQX) –40 125 °C Voltage drop (VP – VN) 2 (1) 5.5 V (1) During transmission of pulses at a high level. 6.4 Thermal Information LMT01-Q1 THERMAL METRIC (1) DQX (WSON) LPG (TO-92) 2 PINS 2 PINS UNIT 177 °C/W RθJA Junction-to-ambient thermal resistance 213 RθJC(top) Junction-to-case (top) thermal resistance 71 94 °C/W RθJB Junction-to-board thermal resistance 81 152 °C/W ψJT Junction-to-top characterization parameter 2.4 33 °C/W ψJB Junction-to-board characterization parameter 79 152 °C/W (1) 4 For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report. Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 6.5 Electrical Characteristics Over operating free-air temperature range and operating VP-VN range (unless otherwise noted). PARAMETER TEST CONDITIONS MIN 150°C (3) 125°C TYP MAX UNIT –0.75 0.75 °C -0.75 0.75 °C 120°C –0.625 0.625 °C 110°C –0.5625 0.5625 °C 100°C VP – VN of 2.15 V to 5.5 V 90°C –0.5625 0.5625 °C –0.5 0.5 °C 25°C –0.5 0.5 °C –20°C –0.5 0.5 °C –30°C –0.5625 0.5625 °C –40°C –0.625 0.625 °C ACCURACY Temperature accuracy (1) (2) ±0.125 PULSE COUNT TRANSFER FUNCTION Number of pulses at 0°C 800 Output pulse range Theoretical max (exceeds device rating) 808 816 15 3228 1 4095 Resolution of one pulse 0.0625 °C OUTPUT CURRENT IOL IOH Output current variation Low level 28 34 40 µA High level 112.5 125 143 µA 3.1 3.7 4.5 40 133 m°C/V 0.002 3.5 µA High-to-Low level output current ratio POWER SUPPLY Accuracy sensitivity to change in VP – VN 2.15 V ≤ VP – VN ≤ 5. 0 V (4) Leakage Current VP – VN VDD ≤ 0.4 V THERMAL RESPONSE Stirred oil thermal response time to 63% of final value DQX (WSON) (package only) LPG (TO-92) 0.4 DQX (WSON) 9.4 LPG (TO-92) 28 Still air thermal response time to 63% of final value (package only) (1) (2) (3) (4) 0.8 s s Calculated using Pulse Count to Temperature LUT and 0.0625°C resolution per pulse, see section Electrical Characteristics - TO92/LPG Pulse Count to Temperature LUT and Electrical Characteristics - WSON/DQX Pulse Count to Temperature LUT. Error can be linearly interpolated between temperatures given in table as shown in the Accuracy vs Temperature curves in section Typical Characteristics. Applicable only for the LPG package. Limit is using end point calculation. Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 5 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com 6.6 Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT Over operating free-air temperature range and 2.15 V ≤ VP – VN ≤ 5. 0 V power supply operating range (unless otherwise noted). LUT is short for Look-up Table. PARAMETER Digital output code MIN TYP MAX –40°C TEST CONDITIONS 172 181 190 –30°C 329 338 347 –20°C 486 494 502 –10°C 643 651 659 0°C 800 808 816 10°C 958 966 974 20°C 1117 1125 1133 30°C 1276 1284 1292 40°C 1435 1443 1451 50°C 1594 1603 1611 60°C 1754 1762 1771 70°C 1915 1923 1931 80°C 2076 2084 2092 90°C 2237 2245 2254 100°C 2398 2407 2416 110°C 2560 2569 2578 120°C 2721 2731 2741 130°C 2883 2894 2905 140°C 3047 3058 3069 150°C 3208 3220 3231 UNIT pulses 6.7 Electrical Characteristics - WSON/DQX Pulse Count to Temperature LUT Over operating free-air temperature range and 2.15 V ≤ VP – VN ≤ 5. 0 V power supply operating range (unless otherwise noted). LUT is short for Look-up Table. PARAMETER Digital output code 6 TEST CONDITIONS MIN TYP MAX –40°C 172 181 190 –30°C 328 338 346 –20°C 486 494 502 –10°C 643 651 659 0°C 800 808 816 10°C 958 966 974 20°C 1117 1125 1133 30°C 1276 1284 1292 40°C 1435 1443 1451 50°C 1594 1602 1611 60°C 1754 1762 1771 70°C 1915 1923 1931 80°C 2076 2084 2092 90°C 2237 2245 2254 100°C 2398 2407 2416 110°C 2560 2569 2578 120°C 2721 2731 2741 125°C 2802 2814 2826 Submit Documentation Feedback UNIT pulses Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 6.8 Switching Characteristics Over operating free-air temperature range and operating VP – VN range (unless otherwise noted). PARAMETER TEST CONDITIONS tR, tF Output current rise and fall time fP Output current pulse frequency MIN CL = 10 pF, RL = 8 k Temperature conversion time (1) tDATA Data transmission time (1) MAX UNIT kHz 1.45 Output current duty cycle tCONV TYP µs 82 88 94 40% 50% 60% 46 50 54 ms 44 47 50 ms 2.15 V to 5.5 V Conversion time includes power up time or device turn on time that is typically 3 ms after POR threshold of 1.2 V is exceeded. 6.9 Timing Diagram tCONV tDATA Power 125µA 34µA tR Power Off Output Current tF 1/fP Figure 1. Timing Specification Waveform Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 7 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com 6.10 Typical Characteristics 1.0 1.0 0.8 Max Limit Temperature Accuracy (ƒC) Temperature Accuracy (ƒC) 0.8 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 Min Limit -0.8 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) 0.0 -0.2 -0.4 -0.6 150 Min Limit ±50 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) C017 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 2.15 V 150 C016 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 2.4 V Figure 2. Accuracy vs LMT01-Q1 Junction Temperature Figure 3. Accuracy vs LMT01-Q1 Junction Temperature 1.0 1.0 0.8 0.8 Max Limit Temperature Accuracy (ƒC) Temperature Accuracy (ƒC) 0.2 -1.0 ±50 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 Min Limit -0.8 Max Limit 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 Min Limit -0.8 -1.0 -1.0 ±50 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) 150 ±50 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) C015 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 2.7 V 150 C014 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 3 V Figure 4. Accuracy vs LMT01-Q1 Junction Temperature Figure 5. Accuracy vs LMT01-Q1 Junction Temperature 1.0 1.0 0.8 0.8 Max Limit Temperature Accuracy (ƒC) Temperature Accuracy (ƒC) 0.4 -0.8 -1.0 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 Min Limit -0.8 Max Limit 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 Min Limit -0.8 -1.0 -1.0 ±50 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) 150 ±50 Figure 6. Accuracy vs LMT01-Q1 Junction Temperature ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) C013 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 4 V 8 Max Limit 0.6 150 C012 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 5 V Figure 7. Accuracy vs LMT01-Q1 Junction Temperature Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 Typical Characteristics (continued) 3.0 1.00 2.5 Max Limit Temperature Accuracy (ƒC) Temperature Accuracy (ƒC) 0.80 0.60 0.40 0.20 0.00 -0.20 -0.40 -0.60 1.0 0.5 0.0 -1.0 -1.00 ±50 ±25 0 25 50 75 100 125 ±50 150 0 25 50 75 100 125 150 C018 C011 Using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT VP – VN = 5.5 V Using Temp = (PC/4096 × 256°C ) – 50°C VP – VN = 2.15 V Figure 9. Accuracy Using Linear Transfer Function Figure 8. Accuracy vs LMT01-Q1 Junction Temperature 3.0 150 2.5 125 Output Current (µA) 2.0 1.5 1.0 0.5 0.0 High Level Current 100 75 Low Level Current 50 25 -0.5 -1.0 0 ±50 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) 150 2 3 4 5 VP - VN (V) C019 Using Temp = (PC/4096 × 256°C ) – 50°C VP – VN = 5.5V 6 C004 TA = 30°C Figure 10. Accuracy Using Linear Transfer Function Figure 11. Output Current vs VP-VN Voltage 150 Percent of (Final - Initial) Value (%) 110 125 Output Current (µA) ±25 LMT01 Junction Temperaure (ƒC) LMT01 Junction Temperature (ƒC) Temperature Accuracy (ƒC) 1.5 -0.5 Min Limit -0.80 2.0 High Level Current 100 75 Low Level Current 50 25 0 100 90 80 70 60 50 40 30 20 10 0 ±50 ±25 0 25 50 75 100 125 LMT01 Juntion Temperature (ƒC) 150 0 120 240 360 480 600 720 840 960 1080 1200 Time (seconds) C003 VP – VN = 3.3 V TINITIAL = 23°C, VP – VN = 3.3 V Figure 12. Output Current vs Temperature C033 TFINAL = 70°C Figure 13. Thermal Response in Still Air (TO92S/LPG Package) Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 9 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com 110 110 100 100 Percent of (Final - Initial) Value (%) Percent of (Final - Initial) Value (%) Typical Characteristics (continued) 90 80 70 60 50 40 30 20 10 0 80 70 60 50 40 30 20 10 0 0 20 40 60 80 100 120 140 160 180 200 Time (seconds) VP – VN = 3.3 V TINITIAL = 23°C, TFINAL = 70°C 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Time (seconds) C032 Air Flow = 2.34 meters/sec Figure 14. Thermal Response in Moving Air (TO92S/LPG Package) 10 90 VP – VN = 3.3 V TINITIAL = 23°C, C031 TFINAL = 70°C Figure 15. Thermal Response in Stirred Oil (TO92S/LPG Package) Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 7 Detailed Description 7.1 Overview The LMT01-Q1 temperature output is transmitted over a single wire using a train of current pulses that typically change from 34 µA to 125 µA. A simple resistor can then be used to convert the current pulses to a voltage. With a 10-kΩ resistor, the output voltage levels range from 340 mV to 1.25 V, typically. A simple microcontroller comparator or external transistor can be used convert this signal to valid logic levels the microcontroller can process properly through a GPIO pin. The temperature can be determined by gating a simple counter on for a specific time interval to count the total number of output pulses. After power is first applied to the device the current level will remain below 34 µA for at most 54 ms while the LMT01-Q1 is determining the temperature. When the temperature is determined, the pulse train begins. The individual pulse frequency is typically 88 kHz. The LMT01-Q1 will continuously convert and transmit data when the power is applied approximately every 104 ms (maximum). The LMT01-Q1 uses thermal diode analog circuitry to detect the temperature. The temperature signal is then amplified and applied to the input of a ΣΔ ADC that is driven by an internal reference voltage. The ΣΔ ADC output is then processed through the interface circuitry into a digital pulse train. The digital pulse train is then converted to a current pulse train by the output signal conditioning circuitry that includes high and low current regulators. The voltage applied across the pins of the LMT01-Q1 is regulated by an internal voltage regulator to provide a consistent Chip VDD that is used by the ADC and its associated circuitry. 7.2 Functional Block Diagram VP Chip VDD Chip VSS Thermal Diode Analog Circuitry Data ADC Interface Voltage Regulator and Output Signal Conditioning VREF LMT01 VN 7.3 Feature Description 7.3.1 Output Interface The LMT01-Q1 provides a digital output in the form of a pulse count that is transmitted by a train of current pulses. After the LMT01-Q1 is powered up, it transmits a very low current of 34 µA for less than 54 ms while the part executes a temperature to digital conversion, as shown in Figure 16. When the temperature-to-digital conversion is complete, the LMT01-Q1 starts to transmit a pulse train that toggles from the low current of 34 µA to a high current level of 125 µA. The pulse train total time interval is at maximum 50 ms. The LMT01-Q1 transmits a series of pulses equivalent to the pulse count at a given temperature as described in Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT. After the pulse count has been transmitted the LMT01-Q1 current level will remain low for the remainder of the 50 ms. The total time for the temperature to digital conversion and the pulse train time interval is 104 ms (maximum). If power is continuously applied, the pulse train output will repeat start every 104 ms (maximum). Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 11 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com Feature Description (continued) Start of data transmission Power ON End of data 54ms max Start of next conversion result data End of data 104ms max Power 50ms max 50ms max Power Off Pulse Train Figure 16. Temperature to Digital Pulse Train Timing Cycle The LMT01-Q1 can be powered down at any time to conserve system power. Take care to ensure that a minimum power-down wait time of 50 ms is used before the device is turned on again. 7.3.2 Output Transfer Function TheLMT01-Q1 outputs at minimum 1 pulse and a theoretical maximum 4095 pulses. Each pulse has a weight of 0.0625°C. One pulse corresponds to a temperature less than –50°C while a pulse count of 4096 corresponds to a temperature greater than 200°C. Note that the LMT01-Q1 is only ensured to operate up to 150°C. Exceeding this temperature by more than 5°C may damage the device. The accuracy of the device degrades as well when 150°C is exceeded. Two different methods of converting the pulse count to a temperature value are discussed in this section. The first method is the least accurate and uses a first order equation, and the second method is the most accurate and uses linear interpolation of the values found in the look-up table (LUT) as described in Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT. The output transfer function appears to be linear and can be approximated by Equation 1: § PC · Temp ¨ u 256qC ¸ 50qC © 4096 ¹ where • • PC is the Pulse Count Temp is the temperature reading (1) Table 1 shows some sample calculations using Equation 1. Table 1. Sample Calculations Using Equation 1 12 TEMPERATURE (°C) NUMBER OF PULSES –40 160 –20 480 0 800 30 1280 50 1600 100 2400 150 3200 Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 The curve shown in Figure 17 shows the output transfer function using equation Equation 1 (blue line) and the look-up table (LUT) found in Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT (red line). The LMT01-Q1 output transfer function as described by the LUT appears to be linear, but upon close inspection, it can be seen as truly not linear. To actually see the difference, the accuracy obtained by the two methods must be compared. 4096 3584 Pulse Count 3072 2560 2048 1536 1024 512 0 ±50 ±25 0 25 50 75 100 125 150 175 200 225 LMT01 Junction Temperature (ƒC) C002 Figure 17. LMT01-Q1 Output Transfer Function For more exact temperature readings the output pulse count can be converted to temperature using linear interpolation of the values found in Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT. 3.0 1.0 2.5 0.8 Temperature Accuracy (ƒC) Temperature Accuracy (ƒC) The curves in Figure 18 and Figure 19, show the accuracy of typical units when using the Equation 1 and linear interpolation using Electrical Characteristics - TO-92/LPG Pulse Count to Temperature LUT, respectively. When compared, the improved performance when using the LUT linear interpolation method can clearly be seen. For a limited temperature range of 25°C to 80°C, the error shown in Figure 18 is flat, so the linear equation will provide good results. For a wide temperature range, TI recommends that linear interpolation and the LUT be used. 2.0 1.5 1.0 0.5 0.0 -0.5 Max Limit 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 Min Limit -0.8 -1.0 -1.0 ±50 ±25 0 25 50 75 100 125 LMT01 Junction Temperaure (ƒC) 150 ±50 Figure 18. LMT01-Q1 Typical Accuracy When Using First Order Equation Equation 1 – 92 Typical Units Plotted at (VP – VN) = 2.15 V ±25 0 25 50 75 100 LMT01 Junction Temperaure (ƒC) C018 125 150 C017 Figure 19. LMT01-Q1 Accuracy Using Linear Interpolation of LUT Found in Electrical Characteristics - WSON/DQX Pulse Count to Temperature LUT – 92 Typical Units Plotted at (VP – VN) = 2.15 V 7.3.3 Current Output Conversion to Voltage The minimum voltage drop across the LMT01-Q1 must be maintained at 2.15 V during the conversion cycle. After the conversion cycle, the minimum voltage drop can decrease to 2.0 V. Thus the LMT01-Q1 can be used for low voltage applications. See Application Information for more information on low voltage operation and other information on picking the actual resistor value for different applications conditions. The resistor value is dependent on the power supply level and the variation and the threshold level requirements of the circuitry the resistor is driving (that is, MCU, GPIO, or Comparator). Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 13 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com Stray capacitance can be introduced when connecting the LMT01-Q1 through a long wire. This stray capacitance influences the signal rise and fall times. The wire inductance has negligible effect on the AC signal integrity. A simple RC time constant model as shown in Figure 20 can be used to determine the rise and fall times. POWER tHL LMT01 VF VHL OUTPUT C 100pF 34 and 125 µA R 10k VS Figure 20. Simple RC Model for Rise and Fall Times § V VS · Ru Cu In ¨ F ¸ © VF VHL ¹ tHL where • • • • RC as shown in Figure 20 VHL is the target high level the final voltage VF = 125 µA × R the start voltage VS = 34 µA × R (2) For the 10% to 90% level rise time (tr), Equation 2 simplifies to: tr = R×C×2.197 (3) Take care to ensure that the LMT01-Q1 voltage drop does not exceed 300 mV under reverse bias conditions, as given in the Absolute Maximum Ratings. 7.4 Device Functional Modes The only functional mode the LMT01-Q1 has is that it provides a pulse count output that is directly proportional to temperature. 14 Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 8 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. 8.1 Application Information 8.1.1 Mounting, Temperature Conductivity, and Self-Heating The LMT01-Q1 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 temperature conductivity. The temperatures of the lands and traces to the leads of the LMT01-Q1 also affect the temperature reading, so they must be a thin as possible. Alternatively, the LMT01-Q1 can be mounted inside a sealed-end metal tube, and then can be dipped into a bath or screwed into a threaded hole in a tank. As with any IC, the LMT01-Q1 and accompanying wiring and circuits must be kept insulated and dry to avoid excessive leakage and corrosion. Printed-circuit coatings are often used to ensure that moisture cannot corrode the leads or circuit traces. The junction temperature of the LMT01-Q1 is the actual temperature being measured by the device. The thermal resistance junction-to-ambient (RθJA) is the parameter (from Thermal Information) used to calculate the rise of a device junction temperature (self-heating) due to its average power dissipation. The average power dissipation of the LMT01-Q1 is dependent on the temperature it is transmitting as it effects the output pulse count and the voltage across the device. Equation 4 is used to calculate the self-heating in the die temperature of the LMT01Q1 (TSH). ª§ tCONV · u VCONV ¸ «¨IOL u t t CONV DATA ¹ ¬«© TSH § ª§ PC tDATA ·º I I · § 4096 PC u OL OH ¸ ¨ u IOL ¸» u ¨ «¨ ¨ © 4096 t 2 CONV tDATA ¹ © 4096 ¹¼ ©¬ º · ¸ u VDATA » u RTJA ¸ ¹ ¼» where • • • • • • • • TSH is the ambient temperature IOL and IOH are the output low and high current level, respectively VCONV is the voltage across the LMT01-Q1 during conversion VDATA is the voltage across the LMT01-Q1 during data transmission tCONV is the conversion time tDATA is the data transmission time PC is the output pulse count RθJA is the junction to ambient package thermal resistance (4) Plotted in the curve Figure 21 are the typical average supply current (black line using left y axis) and the resulting self-heating (red and violet lines using right y axis) during continuous conversions. A temperature range of –50°C to +150°C, a VCONV of 5 V (red line) and 2.15 V (violet line) were used for the self-heating calculation. As can be seen in the curve, the average power supply current and thus the average self-heating changes linearly over temperature because the number of pulses increases with temperature. A negligible self-heating of about 45m°C is observed at 150°C with continuous conversions. If temperature readings are not required as frequently as every 100 ms, self-heating can be minimized by shutting down power to the part periodically thus lowering the average power dissipation. Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 15 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com 60 0.06 50 0.05 40 0.04 30 0.03 20 0.02 10 0.01 Average Current Self Heating at VP-VN=5V Self Heating at VP-VN=2.15V 0 -100 -50 0 50 100 150 Self Heating (ƒC) Average Current (µA) Application Information (continued) 0.00 200 Temperature (ƒC) C001 Figure 21. Average Current Draw and Self-Heating Over Temperature 8.2 Typical Application 8.2.1 3.3-V System VDD MSP430 Interface - Using Comparator Input VDD 3.3V MSP430 GPIO Divider VREF 2.73V or 2.24V VP LMT01 TIMER2 VN COMP_B CLOCK + VR IR = 34 and 125 µA R 6.81k 1% Figure 22. MSP430 Comparator Input Implementation 8.2.1.1 Design Requirements The design requirements listed in are used in the detailed design procedure. Table 2. Design Parameters DESIGN PARAMETER EXAMPLE VALUE VDD 3.3 V VDD minimum 3.0 V LMT01-Q1 VP – VN minimum during conversion 2.15 V LMT01-Q1 VP – VN minimum during data transmission 2.0 V Noise margin 50 mV minimum Comparator input current over temperature range of interest Resistor tolerance 16 < 1 uA 1% Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 8.2.1.2 Detailed Design Procedure First, select the R and determine the maximum logic low voltage and the minimum logic high voltage while ensuring that when the LMT01-Q1 is converting, the minimum (VP – VN) requirement of 2.15 V is met. 1. Select R using minimum VP-VN during data transmission (2 V) and maximum output current of the LMT01Q1 (143.75 µA) – R = (3.0 V – 2 V) / 143.75 µA = 6.993 k the closest 1% resistor is 6.980 k – 6.993 k is the maximum resistance so if using 1% tolerance resistor the actual resistor value needs to be 1% less than 6.993 k and 6.98 k is 0.2% less than 6.993 k thus 6.81 k must be used. 2. Check to see if the 2.15-V minimum voltage during conversion requirement for the LMT01-Q1 is met with the maximum IOL of 39 µA and maximum R of 6.81 k + 1%: – VLMT01 = 3 V – (6.81 k × 1.01) × 39 µA = 2.73 V 3. Find the maximum low level voltage range using the maximum R of 6.81 k and maximum IOL of 39 µA: – VRLmax = (6.81 k × 1.01) × 39 µA = 268 mV 4. Find the minimum high level voltage using the minimum R of 6.81 k and minimum IOH of 112.5 µA: – VRHmin = (6.81 k × 0.99) × 112.5 µA = 758 mV Now select the MSP430 comparator threshold voltage that enables the LMT01-Q1 to communicate to the MSP430 properly. 1. The MSP430 voltage is selected by selecting the internal VREF and then choosing the appropriate 1 of n/32 settings for n of 1 to 31. – VMID= (VRLmax – VRHmin) / 2 + VRHmin = (758 mV – 268 mV) / 2 + 268 mV = 513 mV – n = (VMID / VREF ) × 32 = (0.513 / 2.5) × 32 = 7 2. To prevent oscillation of the comparator, output hysteresis must be implemented. The MSP430 allows this by enabling different n for the rising edge and falling edge of the comparator output. For a falling comparator output transition, N must be set to 6. 3. Determine the noise margin caused by variation in comparator threshold level. Even though the comparator threshold level theoretically is set to VMID, the actual level varies from device to device due to VREF tolerance, resistor divider tolerance, and comparator offset. For proper operation, the COMP_B worst case input threshold levels must be within the minimum high and maximum low voltage levels presented across R, VRHmin and VRLmax, respectively N N_TOL VCHmax VREF u 1 V_REF_TOL u COMP_OFFSET 32 where • • • • • VCLmin VREF is the MSP430 COMP_B reference voltage for this example at 2.5 V V_REF_TOL is the tolerance of the VREF of 1% or 0.01, N is the divisor for the MSP430 or 7 N_TOL is the tolerance of the divisor or 0.5 COMP_OFFSET is the comparator offset specification or 10 mV VREF u 1 V_REF_TOL u N N_TOL 32 (5) COMP_OFFSET where • • • • • VREF is the MSP430 COMP_B reference voltage for this example at 2.5 V, V_REF_TOL is the tolerance of the VREF of 1% or 0.01, N is the divisor for the MSP430 for the hysteresis setting or 6, N_TOL is the tolerance of the divisor or 0.5, COMP_OFFSET is the comparator offset specification or 10 mV (6) The noise margin is the minimum of the two differences: (VRHmin – VCHmax) or (VCHmin – VRLmax) (7) which works out to be 145 mV. Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 17 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com Comparator Threshold and VR VDD Pulse Count Signal VRHmax VRHmin Noise Margin VCHmax VMID VCHmin Noise Margin VRLmax VRLmin GND Time (µs) Figure 23. Pulse Count Signal Amplitude Variation 8.2.1.2.1 Setting the MSP430 Threshold and Hysteresis The comparator hysteresis determines the noise level that the signal can support without causing the comparator to trip falsely and resulting in an inaccurate pulse count. The comparator hysteresis is set by the precision of the MSP430 and what thresholds it is capable of. For this case, as the input signal transitions high, the comparator threshold is dropped by 77 mV. If the noise on the signal is kept below this level as it transitions, the comparator will not trip falsely. In addition, the MSP430 has a digital filter on the COMP_B output that be used to further filter output transitions that occur too quickly. 8.2.1.3 Application Curves Amplitude = 200 mV/div Time Base = 10 µs/div Δy at cursors = 500 mV Δx at cursors = 11.7 µs Figure 24. MSP430 COMP_B Input Signal No Capacitance Load Amplitude = 200 mV/div Time Base = 10 µs/div Δy at cursors = 484 mV Δx at cursors = 11.7 µs Figure 25. MSP430 COMP_B Input Signal 100-pF Capacitance Load 8.3 System Examples The LMT01 device can be configured in a number of ways. Transistor level shifting can be used so that the output pulse of the device can be read with a GPIO (see Figure 26). An isolation block can be inserted to achieve electrical isolation (see Figure 27). Multiple LMT01 devices can be controlled with GPIOs enabling temperature monitor for multiple zones. Lastly, the LMT01 device can be configured to have a common ground with a high side signal (see Figure 29). 18 Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 System Examples (continued) 3.3V VDD MCU/ FPGA/ ASIC VP LMT01 100k VN GPIO MMBT3904 34 and 125 µA 7.5k Figure 26. Transistor Level Shifting 3V to 5.5V 3V to 5.5V ISO734x VCC1 VCC2 VDD VP ISOLATION LMT01 MCU/FPGA/ ASIC Min 2.0V 100k VN GPIO MMBT3904 34 and 125 µA 7.5k GND2 GND1 Figure 27. Isolation VDD 3V to 5.5V GPIO1 GPIO2 GPIO n Up to 2.0m VP VP VP LMT01 U1 LMT01 U2 LMT01 Un VN VN VN MCU/FPGA/ ASIC Min 2.0V GPIO/ COMP 34 and 125 µA 6.81k (for 3V) Note: to turn off an LMT01-Q1 set the GPIO pin connected to VP to high impedance state as setting it low would cause the off LMT01-Q1 to be reverse biased. Comparator input of MCU must be used. Figure 28. Connecting Multiple Devices to One MCU Input Pin Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 19 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com System Examples (continued) 3.3V VDD 34 and 125 µA 7.5k MCU/ FPGA/ ASIC MMBT3906 VP LMT01 GPIO VN 100k Note: the VN of the LMT01-Q1 must be connected to the MCU GND. Figure 29. Common Ground With High-Side Signal 9 Power Supply Recommendations Because the LMT01-Q1 is only a 2-pin device the power pins are common with the signal pins, thus the LMT01Q1 has a floating supply that can vary greatly. The LMT01-Q1 has an internal regulator that provides a stable voltage to internal circuitry. Take care to prevent reverse biasing of the LMT01-Q1 as exceeding the absolute maximum ratings may cause damage to the device. Power supply ramp rate can effect the accuracy of the first result transmitted by the LMT01-Q1. As shown in Figure 30 with a 1-ms rise time, the LMT01-Q1 output code is at 1286, which converts to 30.125°C. The scope photo shown in Figure 31 reflects what happens when the rise time is too slow. In Figure 31, the power supply (yellow trace) is still ramping up to final value while the LMT01-Q1 (red trace) has already started a conversion. This causes the output pulse count to decrease from the previously shown 1286, to 1282 (or 29.875°C). Thus, for slow ramp rates, TI recommends that the first conversion be discarded. For even slower ramp rates, more than one conversion may have to be discarded as TI recommends that either the power supply be within final value before a conversion is used or that ramp rates be faster than 2.5 ms. Yellow trace = 1 V/div, Red trace = 100 mV/div, Time Base = 20 ms/div TA= 30°C LMT01 Pulse Count = 1286 VP-VN = 3.3 V Rise Time = 1 ms Figure 30. Output Pulse Count With Appropriate Power Supply Rise Time 20 Yellow trace = 1V/div, Red trace = 100 mV/div, Time base = 20 ms/div TA=30°C LMT01 Pulse Count = 1282 VP-VN=3.3 V Rise Time = 100 ms Figure 31. Output Pulse Count With Slow Power Supply Rise Time Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 LMT01-Q1 www.ti.com SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 10 Layout 10.1 Layout Guidelines The LMT01-Q1 can be mounted to a PCB as shown in Figure 32 and Figure 33. Take care to make the traces leading to the pads as small as possible to minimize their effect on the temperature the LMT01-Q1 is measuring. 10.2 Layout Example VP VN Figure 32. Layout Example (TO92S/LPG Package) VN VP Figure 33. Layout Example for the DQX (WSON) Package Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 21 LMT01-Q1 SNIS192C – NOVEMBER 2016 – REVISED JUNE 2018 www.ti.com 11 Device and Documentation Support 11.1 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. 11.2 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. 11.3 Trademarks E2E is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 11.4 Electrostatic Discharge Caution This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. 11.5 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 12 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. 22 Submit Documentation Feedback Copyright © 2016–2018, Texas Instruments Incorporated Product Folder Links: LMT01-Q1 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) LMT01ELPGMQ1 ACTIVE TO-92 LPG 2 3000 RoHS & Green SN N / A for Pkg Type -40 to 150 T01G0 LMT01ELPGQ1 ACTIVE TO-92 LPG 2 1000 RoHS & Green SN N / A for Pkg Type -40 to 150 T01G0 LMT01QDQXRQ1 ACTIVE WSON DQX 2 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 125 13M LMT01QDQXTQ1 ACTIVE WSON DQX 2 250 RoHS & Green Call TI Level-1-260C-UNLIM -40 to 125 13M LMT01QLPGMQ1 ACTIVE TO-92 LPG 2 3000 RoHS & Green SN N / A for Pkg Type -40 to 125 T01G1 LMT01QLPGQ1 ACTIVE TO-92 LPG 2 1000 RoHS & Green SN N / A for Pkg Type -40 to 125 T01G1 (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
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