Digital Temperature Sensor and Thermal Watchdog with 2-Wire Interface

Industry-Standard Multi-Sourced Digital Temperature Sensor


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 I²C 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. The host controls the temperature at which the alarm is asserted (TOS) and the hysteresis temperature below which the alarm condition is not valid (THYST). Also, the LM75's TOS and THYST registers 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 TOS = +80°C and THYST = +75°C. The 3.0V to 5.5V supply voltage range, low supply current, and I²C interface make the LM75 ideal for many applications in thermal management and protection.
LM75: Pin Configuration LM75: Pin Configuration Enlarge+

Key Features

  • SO (SOP) and µMAX® (µSOP) Packages
  • I²C 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


  • Computers and Office Electronics
  • Test Equipment
  • Thermal Protection
  • Thermal System Management

Technical Documents

Tutorial 4679 Thermal Management Handbook

Quality and Environmental Data

Product Reliability Reports: LM75.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Related Resources

Type ID PDF Title
Tutorial 4679 Thermal Management Handbook