LM70CILDX-3

LM70 NSC | Alldatasheet

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Technical content

Features

n 0.25˚C temperature resolution. n Shutdown mode conserves power between temperature reading n SPI and MICROWIRE Bus interface n MSOP-8 and LLP-8 packages save space Key Specifications j Supply Voltage 2.65V to 5.5V j Supply Current operating 260µA (typ) 490µA (max) shutdown 12µA (typ) j Temperature Accuracy −10˚C to 65˚C +1.5/−2˚C(max) −55˚C to 125˚C +3/−2˚C(max) −55˚C to 150˚C +3.5/−2˚C(max) Simplified Block Diagram MICROWIRE ® is a registered trademark of National Semiconductor Corporation. DS101223-1 July 2000 LM70 SPI/MICROWIRE10-Bit plus Sign Digital Temperature Sensor © 2000 National Semiconductor Corporation DS101223 www.national.com

Ordering Information

Number Supply Voltage Transport Media LM70CILD-3 T33 LLP-8, LDA08A 2.65V to 3.6V _ Units in Rail LM70CILDX-3 T33 LLP-8, LDA08A 2.65V to 3.6V _ Units in Rail LM70CILD-5 T35 LLP-8, LDA08A 4.5V to 5.5V _ Units in Tape and Reel LM70CILDX-5 T35 LLP-8, LDA08A 4.5V to 5.5V _ Units in Tape and Reel LM70CIMM-3 T04C MSOP-8, MUA08A 2.65V to 3.6V 250 Units in Rail LM70CIMMX-3 T04C MSOP-8, MUA08A 2.65V to 3.6V 3500 Units in Tape and Reel LM70CIMM-5 T03C MSOP-8, MUA08A 4.5V to 5.5V 250 Units in Rail LM70CIMMX-5 T03C MSOP-8, MUA08A 4.5V to 5.5V 3500 Units in Tape and Reel Pin Descriptions Label SOP-8 Pin # LLP-8 Pin # Function Typical Connection SI/O 1 1 Input/Output - Serial bus bi-directional data line. Schmitt trigger input. From and to Controller SC 2 3 Clock - Serial bus clock Schmitt trigger input line. From Controller GND 4 7 Power Supply Ground Ground V+ 5 5 Positive Supply Voltage Input DC Voltage from 2.65V to 5.5V. Bypass with a 0.1 µF ceramic capacitor. CS 7 8 Chip Select input. From Controller NC 3, 6, 8 2, 4, 6 No Connect These pins are not connected to the LM70 die in any way. MSOP-8 DS101223-2 TOP VIEW LLP-8 DS101223-25 TOP VIEW LM70 www.national.com 2

FIGURE 1. COP Microcontroller Interface

Absolute Maximum Ratings(Note 1) Supply Voltage −0.3V to 6.0V Voltage at any Pin −0.3V to V + + 0.3V Input Current at any Pin (Note 2) 5 mA Package Input Current (Note 2) 20 mA Storage Temperature −65˚C to +150˚C Soldering Information, Lead Temperature MSOP-8 and LLP-8 Packages (Note 3) Vapor Phase (60 seconds) Infrared (15 seconds) 215˚C 220˚C ESD Susceptibility (Note 4) Human Body Model 3000V Machine Model 300V Operating Ratings Specified Temperature Range T MIN to TMAX (Note 5) −55˚C to +150˚C Supply Voltage Range (+VS) +2.65V to +5.5V Temperature-to-Digital Converter Characteristics Unless otherwise noted, these specifications apply for V+ = 2.65V to 3.6V for the LM70-3 and V+ = 4.5V to 5.5V for the LM70-5 (Note 6).Boldface limits apply for TA =T J =T MIN to TMAX ;all other limits TA =T J=+25˚C, unless otherwise noted. Parameter Conditions Typical (Note 7) LM70-5 Limits (Note 8) LM70-3 Limits (Note 8) Units (Limit) Temperature Error (Note 6) T A = −10˚C to +65˚C +1.5/−2.0 +1.5/−2.0 ˚C (max) TA = −40˚C to +85˚C ±2.0 ±2.0 ˚C (max) Resolution 11 0.25 Bits Temperature Conversion Time (Note 9) 140 210 210 ms (max) Quiescent Current Serial Bus Inactive 260 490 490 µA (max) Serial Bus Active 260 µA Shutdown Mode 12 µA Logic Electrical Characteristics DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for V+ = 2.65V to 3.6V for the LM70-3 and V+ = 4.5V to 5.5V for the LM70-5.Boldface limits apply for TA =T J =T MIN to TMAX ;all other limits TA =T J=+25˚C, unless otherwise noted. Symbol Parameter Conditions Typical (Note 7) Limits (Note 8) Units (Limit) VIN(1) Logical “1” Input Voltage V+ x 0.7 V (min) V+ + 0.3 V (max) VIN(0) Logical “0” Input Voltage −0.3 V (min) V+ x 0.3 V (max) Input Hysteresis Voltage V + = 2.65V to 3.6V 0.8 0.27 V (min) V+ = 4.5V to 5.5V 0.8 0.35 V (min) IIN(1) Logical “1” Input Current V IN =V + 0.005 3.0 µA (max) IIN(0) Logical “0” Input Current V IN = 0V −0.005 −3.0 µA (min) C IN All Digital Inputs 20 pF VOH High Level Output Voltage I OH = −400 µA 2.4 V (min) VOL Low Level Output Voltage I OL =+ 2m A 0.4 V (max) IO_TRI-STATE TRI-STATE Output Leakage Current VO = GND VO =V + µA (min) µA(max) LM70 www.national.com 4

Logic Electrical Characteristics(Continued) Note 1: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. Note 2:When the input voltage (VI) at any pin exceeds the power supplies (VI< GND or VI> +V S) the current at that pin should be limited to 5 mA. The 20 mA maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 5 mA to four. Note 3:See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” or the section titled “Surface Mount” found in a current National Semicon- ductor Linear Data Book for other methods of soldering surface mount devices. Note 4:Human body model, 100 pF discharged through a 1.5 kΩ resistor. Machine model, 200 pF discharged directly into each pin. Note 5:The life expectancy of the LM70 will be reduced when operating at elevated temperatures. LM70θJA (thermal resistance, junction-to-ambient) when at- tached to a printed circuit board with 2 oz. foil is summarized in the table below: Device Number NS Package Number Thermal Resistance (θJA ) LM70CILD LDA08A 51.3˚C/W LM70CIMM MUA08A 200˚C/W Note 6:Both part numbers of the LM70 will operate properly over the V+ supply voltage range of 2.65V to 5.5V. The temperature error for temperature ranges of −10˚C to +65˚C, −40˚C to +85˚C, −55˚C to +125˚C and −55˚C to +150˚C include error induced by power supply variation of±5% from the nominal value. Tempera- ture error will increase by±0.3˚C for a power supply voltage (V+) variation of±10% from the nominal value. Note 7:Typicals are at TA = 25˚C and represent most likely parametric norm. Note 8:Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 9:This specification is provided only to indicate how often temperature data is updated. The LM70 can be read at any time without regard to conversion state (and will yield last conversion result). A conversion in progress will not be interrupted. The output shift register will be updated at the completionof the read and a new conversion restarted. Note 10: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. LM70 www.national.com 6

Electrical Characteristics

FIGURE 5. Temperature-to-Digital Transfer Function (Non-linear scale for clarity)

Typical Performance Characteristics

1.0 Functional Description

The LM70 temperature sensor incorporates a band-gap type temperature sensor and 10-bit plus sign ΔΣ ADC (Delta-Sigma Analog-to-Digital Converter). Compatibility of the LM70’s three wire serial interface with SPI and MI- CROWIRE allows simple communications with common mi- crocontrollers and processors. Shutdown mode can be used to optimize current drain for different applications. A manu- facture’s ID register identifies the LM70 as National Semi- conductor product.

1.1 POWER UP AND POWER DOWN

The LM70 always powers up in a known state. The power up default condition is continuous conversion mode. Immediatly after power up the LM70 will output an erroneous code until the first temperature conversion has completed. When the supply voltage is less than about 1.6V (typical), the LM70 is considered powered down. As the supply volt- age rises above the nominal 1.6V power up threshold, the in- ternal registers are reset to the power up default state de- scribed above.

1.2 SERIAL BUS INTERFACE

The LM70 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 com- munication 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 TRISTATE ® . 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. Once the 14 bits of data (one sign bit, ten temperature bits and 3 high bits) are transmitted the SI/O line will go into TRI-STATE. CS can be taken high at any time during the transmit phase. If CS is brought low in the middle of a conversion the LM70 will complete the con- version and the output shift register will be updated after CS is brought back high. The receive phase of a communication starts after 16 SC pe- riods. CS can remain low for 32 SC cycles. The LM70 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. A zero in any location will take the LM70 out of shutdown. The following codes only should be transmitted to the LM70:

• 00 hex (normal operation)
• 01 hex (normal operation)
• 03 hex (normal operation)
• 07 hex (normal operation)
• 0F hex (normal operation)
• 1F hex (normal operation)
• 3F hex(normal operation)
• 7F hex(normal operation)
• FF hex (Shutdown, transmit manufacturer’s ID) any others may place the part into a Test Mode. Test Modes are used by National Semiconductor to thoroughly test the function of the LM70 during production testing. Only eight bits have been defined above since only the last eight trans- mitted, before CS is taken HIGH, are detected by the LM70 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 250 ms will have to pass for a conversion to com- plete before the LM70 actually transmits temperature data. Average Power-On Reset Voltage vs Temperature DS101223-23 Static Supply Current vs Temperature DS101223-21 Temperature Error DS101223-22 LM70 www.national.com 8

1.0 Functional Description(Continued)

1.3 TEMPERATURE DATA FORMAT

Temperature data is represented by a 11-bit, two’s comple- ment word with an LSB (Least Significant Bit) equal to 0.25˚C: Temperature Digital Output Binary Hex +150˚C 0100 1011 0001 1111 4B 1Fh +125˚C 0011 1110 1001 1111 3E 9Fh +25˚C 0000 1100 1001 1111 0B 9Fh +0.25˚C 0000 0000 0011 1111 00 3Fh 0˚C 0000 0000 0001 1111 00 1Fh −0.25˚C 1111 1111 1111 1111 FF FFh −25˚C 1111 0011 1001 1111 F3 9Fh −55˚C 1110 0100 1001 1111 E4 9Fh Note: The last two bits are TRI-STATE and depicted as one in the table. The first data byte is the most significant byte with most sig- nificant 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 over- temperature condition, the host processor could immediately take action to remedy the excessive temperatures.

1.4 SHUTDOWN MODE/MANUFACTURER’S ID

Shutdown mode is enabled by writing XX FF to the LM70 as shown in Figure 7c and discussed in Section 1.2. The serial bus is still active when the LM70 is in shutdown. Current draw drops to less than 10 µA between serial communica- tions. When in shutdown mode the LM70 always will output 1000 0001 0000 00XX. This is the manufacturer’s ID/Device ID information. The first 5-bits of the field (1000 0XXX) are reserved for manufacturer’s ID.

1.5 INTERNAL REGISTER STRUCTURE

The LM70 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.

1.5.1 CONFIGURATION REGISTER

(Selects shutdown or continuous conversion modes): (Write Only): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 XXXXXXXX Shutdown D0-D15 set to XX FF hex enables shutdown mode. D0-D15 set to XX 00 hex enables continuous conversion mode. Note: setting D0-D15 to any other values may place the LM70 into a manufacturer’s test mode, upon which the LM70 will stop responding as described. These test modes are to be used for National Semiconductor production testing only. See Section 1.2 Serial Bus Interface for a complete discussion.

1.5.2 TEMPERATURE REGISTER

(Read Only): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 MSB Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 LSB 1 1 1 X X D0–D1: Undefined. TRI-STATE will be output on SI/0. D2–D4: Always set high. D5–D15: Temperature Data. One LSB = 0.25˚C. Two’s complement format.

1.5.3 MANUFACTURER’S/DEVICE ID REGISTER

(Read Only): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 10000001000000XX D0–D1: Undefined. TRI-STATE will be output on SI/0. D2-D4: Always set LOW. D5–D15: Manufacturer’s ID Data. This register is accessed whenever the LM70 is in shutdown mode. LM70 www.national.com9

2.0 Serial Bus Timing Diagrams

3.0 Application Hints

FIGURE 7. Timing Diagrams

4.0 Typical Applications

FIGURE 8. Temperature monitor using Intel 196 processor FIGURE 9. LM70 digital input control using micro-controller’s general purpose I/O.

Physical Dimensionsinches (millimeters) unless otherwise noted 8-Lead Molded Mini Small Outline Package (MSOP) (JEDEC REGISTRATION NUMBER M0-187) Order Number LM70CIMM-3, LM70CIMMX-3, LM70CIMM-5 or LM70CIMMX-5 LM70 www.national.com 12

Physical Dimensionsinches (millimeters) unless otherwise noted (Continued) LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 www.national.com 8-Lead Molded Lead Less Package Order Number LM70CILD-3, LM70CILDX-3, LM70CILD-5 or LM70CILDX-5 LM70 SPI/MICROWIRE10-Bit plus Sign Digital Temperature Sensor National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.