Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsLM75BIMM-3+

General Description

The LM75 temperature sensor includes a delta-sigma

analog-to-digital converter, and a digital overtempera-

ture detector. The host can query the LM75 through its

C interface to read temperature at any time. The

open-drain overtemperature output (OS) sinks current

when the programmable temperature limit is exceeded.

The OS output operates in either of two modes, com-

parator or interrupt. The host controls the temperature

at which the alarm is asserted (T

) and the hysteresis

temperature below which the alarm condition is not

valid (T

HYST

). Also, the LM75’s T

and T

HYST

regis-

ters can be read by the host. The address of the LM75

is set with three pins to allow multiple devices to work

on the same bus. Power-up is in comparator mode, with

defaults of T

= +80°C and T

HYST

= +75°C. The 3.0V

to 5.5V supply voltage range, low supply current, and

C interface make the LM75 ideal for many applica-

tions in thermal management and protection.

Applications

Thermal System Management

Thermal Protection

Test Equipment

Computers and Office Electronics

Features

♦ SO (SOP) and µMAX

(µSOP) Packages

♦ I

C Bus Interface

♦ Separate Open-Drain OS Output Operates as

Interrupt or Comparator/Thermostat Input

♦ Register Readback Capability

♦ Power-Up Defaults Permit Stand-Alone Operation

as a Thermostat

♦ 3.0V to 5.5V Supply Voltage

♦ Low Operating Supply Current 250µA (typ), 1mA

(max)

♦ 4µA (typ) Shutdown Mode Minimizes Power

Consumption

♦ Up to Eight LM75s Can Be Connected to a Single

Bus

♦ Pin- and/or Register-Compatible with Improved-

Performance Maxim Sensors Including MAX7500,

MAX6625, MAX6626, DS75LV, and DS7505

LM75

Digital Temperature Sensor and Thermal

Watchdog with 2-Wire Interface

________________________________________________________________

Maxim Integrated Products

Functional Diagram

Ordering Information/Selector Guide

19-4385; Rev 0; 3/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Note: Devices are specified over the -55°C to +125°C temperature range and include I

C noise filter.

Denotes a lead(Pb)-free/RoHS-compliant package.

T&R = Tape and reel.

PART PIN-PACKAGE PKG SUPPLY VOLTAGE (V) TOP MARK

LM75BIM-3+ 8 SO (SOP) Bulk 3.3 LM75BIM-3

LM75BIMX-3+ 8 SO (SOP) T&R 3.3 LM75BIM-3

LM75BIMM-3+ 8 µMAX (µSOP) Bulk 3.3 T01B

LM75BIMMX-3+ 8 µMAX (µSOP) T&R 3.3 T01B

LM75BIM-5+ 8 SO (SOP) Bulk 5.0 LM75BIM-5

LM75BIMX-5+ 8 SO (SOP) T&R 5.0 LM75BIM-5

LM75BIMM-5+ 8 µMAX (µSOP) Bulk 5.0 T00B

LM75BIMMX-5+ 8 µMAX (µSOP) T&R 5.0 T00B

SDA

SCL

= 3.0V to 5.5V

SILICON

BANDGAP

TEMPERATURE

SENSOR

9-BIT DELTA-

SIGMA ADC

CONFIGURATION

TOS SET POINT

HYST

SET

POINT REGISTER

SET POINT

COMPARATOR W/

HYSTERESIS

2-WIRE INTERFACE

POINTER

8816 16 16

A2GND

SCL

SDA

LM75

μMAX (μSOP), SO

TOP VIEW

Pin Configuration

Summary of content (12 pages)

PAGE 1
9-4385; Rev 0; 3/09 Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface The LM75 temperature sensor includes a delta-sigma analog-to-digital converter, and a digital overtemperature detector. The host can query the LM75 through its I 2 C interface to read temperature at any time. The open-drain overtemperature output (OS) sinks current when the programmable temperature limit is exceeded. The OS output operates in either of two modes, comparator or interrupt.
PAGE 2
LM75 Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface ABSOLUTE MAXIMUM RATINGS (Note 1) +VS to GND ...........................................................-0.3V to +6.0V OS, SDA, SCL to GND...........................................-0.3V to +6.0V All Other Pins to GND .................................-0.3V to (+VS + 0.3V) Input Current at Any Pin (Note 2)..........................................5mA Package Input Current (Note 2)..........................................
PAGE 3
Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface (+VS = +3.0V to +5.5V, unless otherwise noted. Temperature accuracy specifications apply for +VS = 3.3V for versions with “-3” in the suffix and for +VS = 5V for versions with “-5” in the suffix. TA = -55°C to +125°C, unless otherwise noted. Typical values are at +VS = +5V, TA = +25°C.) (Notes 4, 5) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LOGIC (SDA, SCL, A0, A1, A2) Input High Voltage VIH +VS x 0.7 +VS + 0.
PAGE 4
Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) +VS = +5V 270 260 +VS = +3V 250 240 230 5 1.0 +VS = +5V 4 3 +VS = +3V 2 -25 5 35 65 95 TEMPERATURE (°C) 125 0.5 0 -0.5 -1.0 1 -1.5 0 -55 4 TYPICAL PARTS 1.5 ACCURACY (°C) 280 ACCURACY vs. TEMPERATURE 2.0 LM75 toc02 290 6 SHUTDOWN SUPPLY CURRENT (μA) LM75 toc01 300 SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE LM75 toc03 QUIESCENT SUPPLY CURRENT vs.
PAGE 5
Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface The LM75 temperature sensor measures temperature and converts the data into digital form using a bandgap type temperature sensor and a 9-bit delta-sigma ADC. An I2C-compatible 2-wire serial interface allows access to conversion results. The LM75 accepts standard I2C commands to read the data, set the overtemperature alarm (OS) trip thresholds, and configure other characteristics.
PAGE 6
LM75 Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface SDA tBUF tSU:DAT tSU:STA tSU:STO tHD:DAT tLOW tHD:STA SCL tHIGH tHD:STA tR tF START CONDITION (S) ACKNOWLEDGE (A) REPEATED START CONDITION (SR) STOP CONDITION (P) START CONDITION (S) PARAMETERS ARE MEASURED FROM 10% TO 90%. Figure 2. Serial Bus Timing Table 3.
PAGE 7
START BY MASTER START BY MASTER START BY MASTER ADDRESS BYTE REPEAT START BY MASTER ADDRESS BYTE ADDRESS BYTE MOST SIGNIFICANT DATA BYTE ACK BY MASTER ACK BY LM75 POINTER BYTE MOST SIGNIFICANT DATA BYTE ACK BY LM75 ACK BY MASTER LEAST SIGNIFICANT DATA BYTE DATA BYTE NO ACK BY MASTER (c) TYPICAL 1-BYTE READ FROM CONFIGURATION REGISTER WITH PRESET POINTER. ACK BY LM75 STOP COND BY MASTER (b) TYPICAL POINTER SET FOLLOWED BY IMMEDIATE READ FOR 2-BYTE REGISTER SUCH AS TEMP, THIGH, TLOW.
PAGE 8
START BY MASTER START BY MASTER START BY MASTER ADDRESS BYTE ADDRESS BYTE ADDRESS BYTE ACK BY LM75 ACK BY LM75 ACK BY LM75 ACK BY LM75 REPEAT START BY MASTER ADDRESS BYTE POINTER BYTE POINTER BYTE CONFIGURATION BYTE MOST SIGNIFICANT DATA BYTE (c) THIGH AND TLOW WRITE ACK BY LM75 (b) CONFIGURATION REGISTER WRITE ACK BY LM75 STOP COND BY MASTER ACK BY LM75 ACK BY LM75 ACK BY LM75 (a) TYPICAL POINTER SET FOLLOWED BY IMMEDIATE READ FROM CONFIGURATION REGISTER POINTER BYTE LEAST SIGNIFI
PAGE 9
Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface Shutdown Set bit D0 in the Configuration register to 1 to place the LM75 in shutdown mode and reduce supply current to 4µA. In interrupt mode, entering shutdown resets the OS output. While in shutdown, the I2C remains active and T OS and T HYST limit registers along with the Configuration register remain accessible to the master. Fault Queue The fault queue prevents OS false tripping in noisy environments.
PAGE 10
LM75 Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface Table 5. Configuration Register Definition D7 D6 D5 D4 D3 D2 D1 D0 0 0 0 Fault Queue Fault Queue OS Polarity Comparator/ Interrupt Shutdown Configuration Register The 8-bit Configuration register sets the fault queue, OS polarity, shutdown control, and whether the OS output functions in comparator or interrupt mode. When writing to the Configuration register, set bits D7, D6, and D5 to zero (see Table 5).
PAGE 11
Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface LM75 3V to 5.5V 3V to 5.5V 12V R3 10kΩ R1 10kΩ R2 10kΩ R3 10kΩ +VS GND or +V SCL A0 A1 A2 OS N-CHANNEL MOSFET +Vs LM75 SCL SDA SDA 12V 300mA FAN MOTOR R2 10kΩ OS LM75 GND TO Microcontroller GND OS Figure 7. I2C Controlled Temperature Sensor 3V to 5.5V Figure 8. Fan Control C1 0.1μF SHDN OUT- BIAS GND MAX4364 IN+ R1 10kΩ OUT+ INC2 0.1μF +Vs R5 200kΩ OS C4 6.8nF C3 6.
PAGE 12
LM75 Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface Package Information Chip Information PROCESS: CMOS For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 8 SO (SOP) S8-2 21-0041 8 µMAX (µSOP) U8-1 21-0036 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.