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ManualsBrandsNXP SEMICONDUCTORS ManualsSensorsTemperature sensor SMD

1. General description

The LM75B is a temperature-to-digital converter using an on-chip band gap temperature

sensor and Sigma-Delta A-to-D conversion technique with an overtemperature detection

output. The LM75B contains a number of data registers: Configuration register (Conf) to

store the device settings such as device operation mode, OS operation mode, OS polarity

and OS fault queue as described in Section 7 “

Functional description”; temperature

store programmable overtemperature shutdown and hysteresis limits, that can be

communicated by a controller via the 2-wire serial I

C-bus interface. The device also

includes an open-drain output (OS) which becomes active when the temperature exceeds

the programmed limits. There are three selectable logic address pins so that eight devices

can be connected on the same bus without address conflict.

The LM75B can be configured for different operation conditions. It can be set in normal

mode to periodically monitor the ambient temperature, or in shutdown mode to minimize

power consumption. The OS output operates in either of two selectable modes:

OS comparator mode or OS interrupt mode. Its active state can be selected as either

HIGH or LOW. The fault queue that defines the number of consecutive faults in order to

activate the OS output is programmable as well as the set-point limits.

The temperature register always stores an 11-bit two’s complement data giving a

temperature resolution of 0.125 C. This high temperature resolution is particularly useful

in applications of measuring precisely the thermal drift or runaway. When the LM75B is

accessed the conversion in process is not interrupted (that is, the I

C-bus section is totally

independent of the Sigma-Delta converter section) and accessing the LM75B

continuously without waiting at least one conversion time between communications will

not prevent the device from updating the Temp register with a new conversion result. The

new conversion result will be available immediately after the Temp register is updated.

The LM75B powers up in the normal operation mode with the OS in comparator mode,

temperature threshold of 80 C and hysteresis of 75 C, so that it can be used as a

stand-alone thermostat with those pre-defined temperature set points.

2. Features and benefits

 Pin-for-pin replacement for industry standard LM75 and LM75A and offers improved

temperature resolution of 0.125 C and specification of a single part over power supply

range from 2.8 V to 5.5 V

 I

C-bus interface with up to 8 devices on the same bus

 Power supply range from 2.8 V to 5.5 V

 Temperatures range from 55 C to +125 C

LM75B

Digital temperature sensor and thermal watchdog

Rev. 6.1 — 6 February 2015 Product data sheet

Summary of content (37 pages)

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LM75B Digital temperature sensor and thermal watchdog Rev. 6.1 — 6 February 2015 Product data sheet 1. General description The LM75B is a temperature-to-digital converter using an on-chip band gap temperature sensor and Sigma-Delta A-to-D conversion technique with an overtemperature detection output.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog  Frequency range 20 Hz to 400 kHz with bus fault time-out to prevent hanging up the bus  11-bit ADC that offers a temperature resolution of 0.125 C  Temperature accuracy of:  2 C from 25 C to +100 C  3 C from 55 C to +125 C  Programmable temperature threshold and hysteresis set points  Supply current of 1.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 4. Ordering information Table 1. Ordering information Type number Topside mark Package Name Description Version LM75BD LM75BD SO8 plastic small outline package; 8 leads; body width 3.9 mm SOT96-1 LM75BDP LM75B TSSOP8 plastic thin shrink small outline package; 8 leads; body width 3 mm SOT505-1 LM75BGD[1] 75B XSON8U plastic extremely thin small outline package; no leads; 8 terminals; UTLP based; body 3  2  0.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 5. Block diagram VCC LM75B BIAS REFERENCE BAND GAP TEMP SENSOR POINTER REGISTER CONFIGURATION REGISTER COUNTER TEMPERATURE REGISTER TIMER TOS REGISTER COMPARATOR/ INTERRUPT THYST REGISTER 11-BIT SIGMA-DELTA A-to-D CONVERTER OSCILLATOR POWER-ON RESET OS LOGIC CONTROL AND INTERFACE 002aad453 A2 Fig 1. A1 A0 SCL SDA GND Block diagram of LM75B 6. Pinning information 6.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 6.2 Pin description Table 3. Pin description Symbol Pin Description SDA 1 Digital I/O. I2C-bus serial bidirectional data line; open-drain. SCL 2 Digital input. I2C-bus serial clock input. OS 3 Overtemperature Shutdown output; open-drain. GND 4 Ground. To be connected to the system ground. A2 5 Digital input. User-defined address bit 2. A1 6 Digital input. User-defined address bit 1. A0 7 Digital input.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog In OS comparator mode, the OS output behaves like a thermostat. It becomes active when the Temp exceeds the Tth(ots), and is reset when the Temp drops below the Thys. Reading the device registers or putting the device into shutdown does not change the state of the OS output. The OS output in this case can be used to control cooling fans or thermal switches. In OS interrupt mode, the OS output is used for thermal interruption.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 7.2 I2C-bus serial interface The LM75B can be connected to a compatible 2-wire serial interface I2C-bus as a slave device under the control of a controller or master device, using two device terminals, SCL and SDA. The controller must provide the SCL clock signal and write/read data to/from the device through the SDA terminal.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 7.4.1 Pointer register The Pointer register contains an 8-bit data byte, of which the two LSB bits represent the pointer value of the other four registers, and the other 6 MSB bits are equal to 0, as shown in Table 6 and Table 7. The Pointer register is not accessible to the user, but is used to select the data register for write/read operation by including the pointer data byte in the bus command. Table 6.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog Table 8. Conf register …continued Legend: * = default value. Bit Symbol Access Value Description B2 OS_POL R/W OS polarity selection 0* OS active LOW 1 B1 OS active HIGH OS_COMP_INT R/W B0 SHUTDOWN OS operation mode selection 0* OS comparator 1 OS interrupt R/W device operation mode selection 0* normal 1 shutdown 7.4.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog Table 10. Temp register value …continued 11-bit binary (two’s complement) Hexadecimal value Decimal value Value 000 0000 0000 000 0 0.000 C 111 1111 1111 7FF 1 0.125 C 111 0011 1000 738 200 25.000 C 110 0100 1001 649 439 54.875 C 110 0100 1000 648 440 55.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog Table 13. Tos and Thyst limit data and value 11-bit binary (two’s complement) Hexadecimal value Decimal value Value 0 1111 1010 0FA 250 +125.0 C 0 0011 0010 032 50 +25.0 C 0 0000 0001 001 1 +0.5 C 0 0000 0000 000 0 0.0 C 1 1111 1111 1FF 1 0.5 C 1 1100 1110 1CE 50 25.0 C 1 1001 0010 192 110 55.0 C 7.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 7.7 OS fault queue Fault queue is defined as the number of faults that must occur consecutively to activate the OS output. It is provided to avoid false tripping due to noise. Because faults are determined at the end of data conversions, fault queue is also defined as the number of consecutive conversions returning a temperature trip.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 7.10 Protocols for writing and reading the registers The communication between the host and the LM75B must strictly follow the rules as defined by the I2C-bus management. The protocols for LM75B register read/write operations are illustrated in Figure 7 to Figure 12 together with the following definitions: 1. Before a communication, the I2C-bus must be free or not busy.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 1 2 3 4 1 0 0 1 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 0 0 0 0 0 0 0 1 A 0 0 0 4 5 6 7 8 9 SCL SDA S A2 A1 A0 W A device address START pointer byte write P configuration data byte device acknowledge device acknowledge Fig 7.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (next) SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 device address 0 0 device acknowledge 3 4 P0 (next) A device acknowledge write 2 P1 pointer byte START 1 0 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (cont.) SDA (cont.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 8. Application design-in information 8.1 Typical application power supply 0.1 μF BUS 10 kΩ PULL-UP RESISTORS 10 kΩ SCL I2C-BUS SDA A2 DIGITAL LOGIC 10 kΩ VCC A1 A0 8 2 1 LM75B 3 OS DETECTOR OR INTERRUPT LINE 5 6 7 4 GND 002aad457 Fig 13. Typical application 8.2 LM75A and LM75B comparison Table 15.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog [5] The LM75B performs the temperature-to-data conversions with a much higher speed than the LM75A. While the LM75A takes almost the whole of conversion period (Tconv) time of about 100 ms to complete a conversion, the LM75B takes only about 1⁄10 of the period, or about 10 ms. Therefore, the conversion period (Tconv) is the same, but the temperature conversion time (tconv(T)) is different between the two parts.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog VOL(EVENT) = 0.4 V IOL(sink)EVENT = 3 mA Rth(j-a) = 56 C/W Self heating due to power dissipation is: T = 56    3.6  0.4  +  0.4  3  +  0.4  1   = 56 C  W  3.04 mW = 0.17 C (2) 8.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 9. Limiting values Table 16. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Symbol Parameter Conditions Min Max Unit VCC supply voltage 0.3 +6.0 V VI input voltage at input pins 0.3 +6.0 V II input current at input pins 5.0 +5.0 mA IO(sink) output sink current on pin OS - 10.0 mA VO output voltage on pin OS 0.3 +6.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 11. Static characteristics Table 18. Static characteristics VCC = 2.8 V to 5.5 V; Tamb = 55 C to +125 C; unless otherwise specified. Symbol Parameter Conditions Min Typ[1] Max Unit Tacc temperature accuracy Tamb = 25 C to +100 C 2 - +2 C Tamb = 55 C to +125 C 3 - +3 C Tres temperature resolution 11-bit digital temp data - 0.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 002aae198 300 IDD(AV) (μA) 200 IDD(AV) (μA) VCC = 5.5 V 4.5 V 3.3 V 2.8 V 100 0 −75 −25 25 75 002aae200 0.5 IDD(sd) (μA) 0.4 VCC = 5.5 V 4.5 V 3.3 V 2.8 V 0.3 0 −75 125 Tamb (°C) Fig 14. Average supply current versus temperature; I2C-bus inactive 0.3 0.1 0.1 −25 25 75 0 −75 125 Tamb (°C) Fig 16. Shutdown mode supply current versus temperature 25 75 125 Tamb (°C) 002aae201 0.5 VOL(OS) (V) 0.4 0.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 12. Dynamic characteristics Table 19. I2C-bus interface dynamic characteristics[1] VCC = 2.8 V to 5.5 V; Tamb = 55 C to +125 C; unless otherwise specified. Symbol Parameter Conditions Min Typ Max Unit fSCL SCL clock frequency see Figure 20 0.02 - 400 kHz tHIGH HIGH period of the SCL clock 0.6 - - s tLOW LOW period of the SCL clock 1.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 13. Package outline SO8: plastic small outline package; 8 leads; body width 3.9 mm SOT96-1 D E A X c y HE v M A Z 5 8 Q A2 A (A 3) A1 pin 1 index θ Lp 1 L 4 e detail X w M bp 0 2.5 5 mm scale DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT A max. A1 A2 A3 bp c D (1) E (2) e HE L Lp Q v w y Z (1) mm 1.75 0.25 0.10 1.45 1.25 0.25 0.49 0.36 0.25 0.19 5.0 4.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog TSSOP8: plastic thin shrink small outline package; 8 leads; body width 3 mm D E SOT505-1 A X c y HE v M A Z 5 8 A2 pin 1 index (A3) A1 A θ Lp L 1 4 detail X e w M bp 0 2.5 5 mm scale DIMENSIONS (mm are the original dimensions) UNIT A max. A1 A2 A3 bp c D(1) E(2) e HE L Lp v w y Z(1) θ mm 1.1 0.15 0.05 0.95 0.80 0.25 0.45 0.25 0.28 0.15 3.1 2.9 3.1 2.9 0.65 5.1 4.7 0.94 0.7 0.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog XSON8: plastic extremely thin small outline package; no leads; 8 terminals; body 3 x 2 x 0.5 mm B D SOT996-2 A E A A1 detail X terminal 1 index area e1 1 4 8 5 C C A B C v w b e L1 y y1 C L2 L X 0 1 2 mm scale Dimensions (mm are the original dimensions) Unit(1) mm max nom min A A1 b 0.05 0.35 D E 2.1 3.1 0.5 0.00 0.15 1.9 e e1 0.5 1.5 2.9 L L1 L2 0.5 0.15 0.6 0.3 0.05 0.4 v 0.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog HWSON8: plastic thermal enhanced very very thin small outline package; no leads; 8 terminals; body 2 x 3 x 0.75 mm SOT1069-2 X B D A A2 A E A1 A3 terminal 1 index area detail X e1 terminal 1 index area e 1 4 C C A B C v w b y y1 C L K E2 8 5 D2 0 1 scale Dimensions Unit mm 2 mm A(1) A1 A2 max 0.80 0.05 0.65 nom 0.75 0.02 0.55 min 0.70 0.00 0.45 A3 b D(1) D2 E(1) E2 0.2 0.30 0.25 0.18 2.1 2.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 14. Soldering of SMD packages This text provides a very brief insight into a complex technology. A more in-depth account of soldering ICs can be found in Application Note AN10365 “Surface mount reflow soldering description”. 14.1 Introduction to soldering Soldering is one of the most common methods through which packages are attached to Printed Circuit Boards (PCBs), to form electrical circuits.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 14.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog temperature maximum peak temperature = MSL limit, damage level minimum peak temperature = minimum soldering temperature peak temperature time 001aac844 MSL: Moisture Sensitivity Level Fig 25. Temperature profiles for large and small components For further information on temperature profiles, refer to Application Note AN10365 “Surface mount reflow soldering description”.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 15. Soldering: PCB footprints 5.50 0.60 (8×) 1.30 4.00 6.60 7.00 1.27 (6×) solder lands occupied area placement accuracy ± 0.25 Dimensions in mm sot096-1_fr Fig 26. PCB footprint for SOT96-1 (SO8); reflow soldering 1.20 (2×) 0.60 (6×) enlarged solder land 0.3 (2×) 1.30 4.00 6.60 7.00 1.27 (6×) 5.50 board direction solder lands occupied area solder resist placement accurracy ± 0.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 3.600 2.950 0.125 0.725 0.125 5.750 3.200 3.600 5.500 1.150 0.600 0.450 0.650 solder lands occupied area Dimensions in mm sot505-1_fr Fig 28. PCB footprint for SOT505-1 (TSSOP8); reflow soldering LM75B Product data sheet All information provided in this document is subject to legal disclaimers. Rev. 6.1 — 6 February 2015 © NXP B.V. 2015. All rights reserved.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 2.400 pa + oa 2.000 0.500 0.500 0.250 0.025 0.025 4.250 3.400 pa + oa 2.000 4.000 0.900 solder lands placement area solder paste occupied area Dimensions in mm sot996-2_fr Fig 29. PCB footprint for SOT996-2 (XSON8U); reflow soldering LM75B Product data sheet All information provided in this document is subject to legal disclaimers. Rev. 6.1 — 6 February 2015 © NXP B.V. 2015. All rights reserved.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 16. Abbreviations Table 22. Abbreviations Acronym Description A-to-D Analog-to-Digital CDM Charged-Device Model ESD ElectroStatic Discharge HBM Human Body Model I2C-bus Inter-Integrated Circuit bus I/O Input/Output LSB Lease Significant Bit LSByte Least Significant Byte MSB Most Significant Bit MSByte Most Significant Byte POR Power-On Reset 17. Revision history Table 23.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 18. Legal information 18.1 Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog Export control — This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from competent authorities. Non-automotive qualified products — Unless this data sheet expressly states that this specific NXP Semiconductors product is automotive qualified, the product is not suitable for automotive use.
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LM75B NXP Semiconductors Digital temperature sensor and thermal watchdog 20. Contents 1 2 3 4 4.1 5 6 6.1 6.2 7 7.1 7.2 7.2.1 7.3 7.4 7.4.1 7.4.2 7.4.3 7.4.4 7.5 7.6 7.7 7.8 7.9 7.10 8 8.1 8.2 8.3 8.4 9 10 11 12 13 14 14.1 14.2 14.3 14.4 15 16 17 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features and benefits . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Ordering information . . . . . . . . . . . . . . . . . . . .