PhilipsSemicondu ctorsLM75ADigital temperatu re sensor andthermal Watchdog™Produ ct data sheetSu persedes data of 2001 Ju l 162004 Oct 05INTEGRATED CIRCUITSPhilips Semicondu ctorsProdu ct data sheetLM75ADigital temperatu re sensor and thermal Watchdog™22004 Oct 05GENERAL DESCRIPTIONThe LM75A is a temperature-to-digital converter using an on-chipband-gap temperature sensor and Sigma-delta A-to-D conversiontechnique. The device is also a thermal detector providing anover-temp detection output. The LM75A contains a number of dataregisters: Configuration register (Conf) to store the device settingssuch as device operation mode, OS operation mode, OS polarityand OS fault queue as described in the functional descriptionsection; temperature register (Temp) to store the digital tempreading, and set-point registers (Tos & Thyst) to store programmableovertemp shutdown and hysteresis limits, that can be communicatedby a controller via the 2-wire serial I2C-bus interface. The devicealso includes an open-drain output (OS) which becomes activewhen the temperature exceeds the programmed limits. There arethree selectable logic address pins so that eight devices can beconnected on the same bus without address conflict.The LM75A can be configured for different operation conditions. Itcan be set in normal mode to periodically monitor the ambienttemperature, or in shutdown mode to minimize power consumption.The OS output operates in either of two selectable modes: OScomparator mode and OS interrupt mode. Its active state can beselected as either HIGH or LOW. The fault queue that defines thenumber of consecutive faults in order to activate the OS output isprogrammable as well as the set-point limits.The temperature register always stores an 11-bi...
