LM71CIMF/NOPB

LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 LM71/LM71-Q1 SPI/MICROWIRE 13-Bit Plus Sign Temperature Sensor 1 Features 2 Applications • • • • • • • • • 1 • • • • LM71Q is AEC-Q100 Grade 0 Qualified and is Manufactured on an Automotive Grade Flow 5-Pin SOT-23 Package or 6-Pin No-Pull-Back WSON Package Operates Over a Full −40°C to +150°C Range SPI and MICROWIRE Bus Interface Key Specifications: – Supply Voltage: 2.65V to 5.5V – Supply Current – Operating: 300 µA (typ) – 550 µA (max) – Temperature Accuracy – −10°C to +65°C: ±1.5°C (max) – −40°C to 150°C: +3/− 2°C (max) – Temperature Resolution: 31.25 m°C System Thermal Management Personal Computers Portable Electronic Devices Disk Drives Office Electronics Electronic Test Equipment Vending Machines Automotive 3 Description The LM71 is a low-power, high-resolution digital temperature sensor with an SPI and MICROWIRE compatible interface, available in the 5-pin SOT-23 or the 6-pin WSON (no pull back) package. The host can query the LM71 at any time to read temperature. Its low operating current is useful in systems where low power consumption is critical. The LM71 has 13-bit plus sign temperature resolution (0.03125°C per LSB) while operating over a temperature range of −40°C to +150°C. The LM71’s 2.65V to 5.5V supply voltage range, fast conversion rate, low supply current, and simple SPI interface make it ideal for a wide range of applications. The LM71Q is available in the 5-lead SOT-23 package only. Simplified Block Diagram 2.65V to 5.5V 14-Bit Delta-Sigma A/D Converter Temperature Sensor Circuitry LM71 Control Logic CS Temperature Register Three-Wire Serial Interface Manufacturer's ID Register SI/O SC 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. LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 www.ti.com 3.1 Connection Diagram CS 1 GND 2 SI/O 3 5 V+ SC 1 GND 2 SI/O 3 LM71 6 V+ 5 GND 4 CS LM71 4 SC Figure 1. 5-Pin SOT-23 See Package Number DBV Figure 2. 6-Pin WSON No Pull-Back See Package Number NGG0006A Table 1. PIN DESCRIPTIONS Label Pin Number SOT-23-5 Function Typical Connection WSON-6 CS 1 4 GND 2 2, 5 Chip Select input From controller Power Supply Ground Connect all GND Pins to ground From and to controller SI/O 3 3 Slave Input/Output - Serial bus bi-directional data line. Schmitt trigger input. SC 4 1 Slave Clock - Serial bus clock Schmitt trigger input line From controller V+ 5 6 Positive Supply Voltage Input DC voltage from 2.65V to 5.5V. Bypass with a 0.1 μF ceramic capacitor. 3.2 Typical Application Figure 3. COP Microcontroller Interface 3.1 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. 3.2 Trademarks All trademarks are the property of their respective owners. 2 Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 LM71, LM71-Q1 www.ti.com SNIS125E – MARCH 2004 – REVISED AUGUST 2018 4 Absolute Maximum Ratings (1) −0.3V to 6.0V Supply Voltage −0.3V to V+ + 0.3V Voltage at any Pin Input Current at any Pin (2) 5 mA −65°C to +150°C Storage Temperature Soldering Information, Lead Temperature SOT-23-5 Package WSON-6 Package ESD Susceptibility (3) (1) (2) (3) Vapor Phase (60 seconds) 215°C Infrared (15 seconds) 220°C Infrared (5 seconds) 215°C Human Body Model 2000V Machine Model 200V Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating the device beyond its rated operating conditions. When the input voltage (VI) at any pin exceeds the power supplies (VI < GND or VI > +VS) the current at that pin should be limited to 5 mA. Human body model, 100 pF discharged through a 1.5 kΩ resistor. Machine model, 200 pF discharged directly into each pin. 5 Operating Ratings Specified Temperature Range (1) (TMIN to TMAX) LM71CIMF, LM71CISD, LM71QCIMF −40°C to +150°C Supply Voltage Range (+VS) LM71CIMF, LM71CISD, LM71QCIMF +2.65V to +5.5V (1) The life expectancy of the LM71 will be reduced when operating at elevated temperatures. LM71 θJA (thermal resistance, junction-toambient) when attached to a printed circuit board with 2 oz. foil is summarized in the table below: Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 3 LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 www.ti.com Device Number Thermal Resistance (θJA) LM71CIMF/LM71QCIMF 250°C/W LM71CISD 57.6°C/W 6 Temperature-to-Digital Converter Characteristics Unless otherwise noted, these specifications apply for V+ = 2.65V to 3.6V (1). Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25°C, unless otherwise noted. LM71CIMF LM71CISD Limits (3) Units (Limit) ±1.5 °C (max) TA = −40°C to +85°C ±2.0 °C (max) TA = −40°C to +150°C +3/−2 °C (max) Parameter Typical (2) Conditions TA = −10°C to +65°C Temperature Error (1) (4) 14 0.03125 Resolution Bits °C Temperature Conversion Time See (5) 200 270 ms (max) Quiescent Current Serial Bus Inactive 300 550 μA (max) The LM71 will operate properly over the V+ supply voltage range of 2.65V to 5.5V. Typicals are at TA = 25°C and represent most likely parametric norm. Limits are ensured to AOQL (Average Outgoing Quality Level). For best accuracy, minimize output loading. Higher sink currents can affect sensor accuracy with internal heating. This can cause an error of 0.64°C at full rated sink current and saturation voltage based on junction-to-ambient thermal resistance. Following a power on reset, the user must allow at least 270 ms before making the first read transaction to ensure a first valid temperature read. After the first read, in order to ensure an accurate temperature result, the time interval between any two consecutive temperature reads must be greater than the maximum conversion time of 270 ms. For more information, refer to SNLA296. (1) (2) (3) (4) (5) 7 Logic Electrical Characteristics DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for V+ = 2.65V to 3.6V (1). Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25°C, unless otherwise noted. Symbol Parameter VIN(1) Logical “1” Input Voltage VIN(0) Logical “0” Input Voltage Conditions V+ = 3.0V to 3.6V IIN(1) Logical “1” Input Current IIN(0) Logical “0” Input Current CIN All Digital Inputs VOH High Level Output Voltage VOL (1) (2) (3) 4 Limits (3) Units (Limit) V+ × 0.7 V (min) V+ + 0.3 V (max) −0.3 V (min) + V (max) V × 0.3 Input Hysteresis Voltage IO_TRI-STATE Typical (2) 0.4 0.33 V (min) VIN = V+ 0.005 3.0 μA (max) VIN = 0V −0.005 −3.0 μA (min) IOH = −400 μA 2.4 V (min) Low Level Output Voltage IOL = +2 mA 0.4 V (max) TRI-STATE Output Leakage Current VO = GND VO = V+ −1 +1 μA (min) μA (max) 20 pF The LM71 will operate properly over the V+ supply voltage range of 2.65V to 5.5V. Typicals are at TA = 25°C and represent most likely parametric norm. Limits are ensured to AOQL (Average Outgoing Quality Level). Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 LM71, LM71-Q1 www.ti.com SNIS125E – MARCH 2004 – REVISED AUGUST 2018 SERIAL BUS DIGITAL SWITCHING CHARACTERISTICS Unless otherwise noted, these specifications apply for V+ = 2.65V to 3.6V (1); CL (load capacitance) on output lines = 100 pF unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25°C, unless otherwise noted. Symbol Parameter Conditions Typical (2) Limits (3) Units (Limit) μs (min) (max) t1 SC (Clock) Period 0.16 DC t2 CS Low to SC (Clock) High Set-Up Time 100 ns (min) t3 CS Low to Data Out (SO) Delay 70 ns (max) t4 SC (Clock) Low to Data Out (SO) Delay 70 ns (max) t5 CS High to Data Out (SO) TRI-STATE 200 ns (max) t6 SC (Clock) High to Data In (SI) Hold Time 50 ns (min) t7 Data In (SI) Set-Up Time to SC (Clock) High 30 ns (min) tr SC (Clock) Rise Time 100 ns (max) tf SC (Clock) Fall Time 100 ns (max) (1) (2) (3) + The LM71 will operate properly over the V supply voltage range of 2.65V to 5.5V. Typicals are at TA = 25°C and represent most likely parametric norm. Limits are ensured to AOQL (Average Outgoing Quality Level). 30% 30% t4 t2 CS 70% 70% SC t4 70% 30% tf tr 70% 30% t3 70% SO 30% Figure 4. Data Output Timing Diagram SC CS 70% t5 70% SO 30% Figure 5. TRI-STATE Data Output Timing Diagram Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 5 LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 www.ti.com SC 70% 30% t7 CS t6 SI 70% 30% Figure 6. Data Input Timing Diagram Figure 7. Temperature-to-Digital Transfer Function (Non-linear scale for clarity) Figure 8. TRI-STATE Test Circuit 6 Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 LM71, LM71-Q1 www.ti.com SNIS125E – MARCH 2004 – REVISED AUGUST 2018 8 Typical Performance Characteristics Figure 9. Static Supply Current vs. Temperature Figure 10. Temperature Error Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 7 LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 www.ti.com 9 Functional Description The LM71 temperature sensor incorporates a temperature sensor and 13-bit plus sign ΔΣ ADC (Delta-Sigma Analog-to-Digital Converter). Compatibility of the LM71's three wire serial interface with SPI and MICROWIRE allows simple communications with common microcontrollers and processors. Shutdown mode can be used to optimize current drain for different applications. A Manufacture's/Device ID register identifies the LM71 as TI product. 9.1 POWER UP AND POWER DOWN The LM71 always powers up in a known state. The power up default condition is continuous conversion mode. Immediately after power up the LM71 will output an erroneous code until the first temperature conversion has completed. When the supply voltage is less than about 1.6V (typical), the LM71 is considered powered down. As the supply voltage rises above the nominal 1.6V power up threshold, the internal registers are reset to the power up default state described above. 9.2 SERIAL BUS INTERFACE The LM71 operates as a slave and is compatible with SPI or MICROWIRE bus specifications. Data is clocked out on the falling edge of the serial clock (SC), while data is clocked in on the rising edge of SC. A complete transmit/receive communication will consist of 32 serial clocks. The first 16 clocks comprise the transmit phase of communication, while the second 16 clocks are the receive phase. When CS is high SI/O will be in TRI-STATE. Communication should be initiated by taking chip select (CS) low. This should not be done when SC is changing from a low to high state. Once CS is low the serial I/O pin (SI/O) will transmit the first bit of data. The master can then read this bit with the rising edge of SC. The remainder of the data will be clocked out by the falling edge of SC. CS can be taken high at any time during the transmit phase. If CS is brought low in the middle of a conversion the LM71 will complete the conversion and the output shift register will be updated after CS is brought back high. The receive phase of a communication starts after 16 SC periods. CS can remain low for 32 SC cycles. The LM71 will read the data available on the SI/O line on the rising edge of the serial clock. Input data is to an 8-bit shift register. The part will detect the last eight bits shifted into the register. The receive phase can last up to 16 SC periods. All ones must be shifted in order to place the part into shutdown. All zeros must be shifted in order to place the LM71 into continuous conversion mode. Only the following codes should be transmitted to the LM71: • 00 hex for continuous conversion • FF hex for shutdown Another code may place the part into a test mode. Test modes are used by TI to thoroughly test the function of the LM71 during production testing. Only eight bits have been defined above since only the last eight transmitted are detected by the LM71, before CS is taken HIGH. The following communication can be used to determine the Manufacturer's/Device ID and then immediately place the part into continuous conversion mode. With CS continuously low: • Read 16 bits of temperature data • Write 16 bits of data commanding shutdown • Read 16 bits of Manufacture's/Device ID data • Write 8 to 16 bits of data commanding Conversion Mode • Take CS HIGH. Note that 300 ms will have to pass for a conversion to complete before the LM71 actually transmits temperature data. 8 Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 LM71, LM71-Q1 www.ti.com SNIS125E – MARCH 2004 – REVISED AUGUST 2018 9.3 TEMPERATURE DATA FORMAT Temperature data is represented by a 14-bit, two's complement word with an LSB (Least Significant Bit) equal to 0.03125°C: Digital Output Temperature Binary Hex +150°C 0100 1011 0000 0011 4B03 +125°C 0011 1110 1000 0011 3E83 +25°C 0000 1100 1000 0011 0C83 +0.03125°C 0000 0000 0000 0111 0007 0°C 0000 0000 0000 0011 0003 −0.03125°C 1111 1111 1111 1111 FFFF −25°C 1111 0011 1000 0011 F383 −40°C 1110 1100 0000 0011 EC03 The first data byte is the most significant byte with most significant bit first, permitting only as much data as necessary to be read to determine temperature condition. For instance, if the first four bits of the temperature data indicate an overtemperature condition, the host processor could immediately take action to remedy the excessive temperatures. 9.4 SHUTDOWN MODE/MANUFACTURER'S ID Shutdown mode is enabled by writing XX FF to the LM71 as shown in Figure 13. The serial bus is still active when the LM71 is in shutdown. When in shutdown mode the LM71 always will output 1000 0000 0000 1111. This is the manufacturer's/Device ID information. The first 5-bits of the field (1000 0XXX) are reserved for manufacturer's ID. 9.5 INTERNAL REGISTER STRUCTURE The LM71 has three registers, the temperature register, the configuration register and the manufacturer's/device identification register. The temperature and manufacturer's/device identification registers are read only. The configuration register is write only. 9.5.1 Configuration Register (Selects shutdown or continuous conversion modes): Table 2. (Write Only): D15 D14 D13 D12 D11 D10 D9 D8 X X X X X X X X D7 D6 D5 D4 D3 D2 D1 D0 Shutdown D0–D15 set to XX FF hex enables shutdown mode. D0–D15 set to 00 00 hex sets Continuous conversion mode. Note: setting D0-D15 to any other values may place the LM70 into a manufacturer's test mode, upon which the LM71 will stop responding as described. These test modes are to be used for TI production testing only. See SERIAL BUS INTERFACE for a complete discussion. Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 9 LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 www.ti.com 9.5.2 Temperature Register Table 3. (Read Only): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 MSB Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit1 LSB 1 1 D0–D1: Logic 1 will be output on SI/0. D2–D15: Temperature Data. One LSB = 0.03125°C. Two's complement format. 9.5.3 Manufacturer/Device ID Register Table 4. (Read Only): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 1 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 D0–D1: Logic 1 will be output on SI/0. D2–D15: Manufacturer's/Device ID Data. This register is accessed whenever the LM71 is in shutdown mode. 9.6 Serial Bus Timing Diagrams Figure 11. Reading Continuous Conversion - Single Eight-Bit Frame Figure 12. Reading Continuous Conversion - Two Eight-Bit Frames Figure 13. Writing Shutdown Control 10 Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 LM71, LM71-Q1 www.ti.com SNIS125E – MARCH 2004 – REVISED AUGUST 2018 9.7 Application Hints To get the expected results when measuring temperature with an integrated circuit temperature sensor like the LM71, it is important to understand that the sensor measures its own die temperature. For the LM71, the best thermal path between the die and the outside world is through the LM71's pins. In the SOT-23 package, all the pins on the LM71 will have an equal effect on the die temperature. Because the pins represent a good thermal path to the LM71 die, the LM71 will provide an accurate measurement of the temperature of the printed circuit board on which it is mounted. There is a less efficient thermal path between the plastic package and the LM71 die. If the ambient air temperature is significantly different from the printed circuit board temperature, it will have a small effect on the measured temperature. In probe-type applications, the LM71 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 LM71 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. Printed-circuit coatings and varnishes such as Humiseal and epoxy paints or dips are often used to insure that moisture cannot corrode the LM71 or its connections. 9.8 Typical Applications Figure 14. Temperature monitor using Intel 196 processor Figure 15. LM71 digital input control using micro-controller's general purpose I/O. Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 11 LM71, LM71-Q1 SNIS125E – MARCH 2004 – REVISED AUGUST 2018 www.ti.com 10 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision D (March 2013) to Revision E • Added SNLA296 ulink to the temperature conversion time tablenote.................................................................................... 4 Changes from Revision C (March 2013) to Revision D • 12 Page Page Changed layout of National Semiconductor Data Sheet to TI format .................................................................................. 11 Submit Documentation Feedback Copyright © 2004–2018, Texas Instruments Incorporated Product Folder Links: LM71 LM71-Q1 PACKAGE OPTION ADDENDUM www.ti.com 4-May-2022 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) Samples (4/5) (6) LM71CIMF NRND SOT-23 DBV 5 1000 Non-RoHS & Green Call TI Level-1-260C-UNLIM T16C LM71CIMF/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM T16C Samples LM71CIMFX/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 150 T16C Samples LM71CISD/NOPB ACTIVE WSON NGG 6 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 150 L71CI Samples LM71QCIMF/NOPB ACTIVE SOT-23 DBV 5 1000 RoHS & Green SN Level-1-260C-UNLIM -40 to 150 T16Q Samples LM71QCIMFX/NOPB ACTIVE SOT-23 DBV 5 3000 RoHS & Green SN Level-1-260C-UNLIM -40 to 150 T16Q Samples (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