LM75 I2C Temperature Sensor From Rikipedia Embedded Wiki
LM75 is a very commonly used Digital temperature sensor in embedded systems. You will find these sensors on single board computers and small embedded systems, where these sensors measure temperature around a localized area on the board or around the processor. Many vendors make similar kind of digital temperature sensors with difference in ADC resolution and number of sensors which can be connected on same I2C Bus.
LM75 is an industry standard Digita temperature sensor with integrated 9-bit ADC (Sigma-Delta). Some of the similar sensor can provide readings with a resolution of 12-bit e.g. (TMP175, TMP75 etc.). This sensor works on I2C Protocol and act as a slave device on I2C Bus. This single chip sensor also has thermostat controls which can be configured as per user requirements.
Basic Block diagram of LM75/TMP75/TMP175 Sensor
The typical connection diagram for TMP75 where SCL and SDA pins goes to microcontroller or processor's I2C controller. Address line pins (A0, A1, A2) are internally pulled up and can be configured as per hardware designer, if left unconnected they will have a value of 1.
The thermostat pin is an output signal can be connected to controller or processor GPIO to indicate fault event.