The MAX31629 I2Cdigital thermometer and real-time clock (RTC) integrates the critical functions of a real-time clock and a temperature monitor in a small-outline 8-pin TDFN package. Communication to the device is accomplished through an I2C interface. The wide power-supply range and minimal power requirement of the device allow for accurate time/temperature measurements in battery-powered applications.

The digital thermometer provides 9-bit to 12-bit temperature readings that indicate the temperature of the device.

No additional components are required; the device is truly a “temperature-to-digital” converter.

The clock/calendar provides seconds, minutes, hours, day, day of the week, month, day of the month, and year. The end-of-the-month date is automatically adjusted for months with less than 31 days, including corrections for leap years. It operates in either a 12- or 24-hour format with AM/PM indicator in 12-hour mode. The crystal oscillator frequency is internally divided, as specified by device configuration. An open-drain output is provided that can be used as the oscillator input for a microcontroller.

The open-drain alarm output of the device becomes active when either the measured temperature exceeds the programmed overtemperature limit (TH) or current time reaches the programmed alarm setting. The user can configure which event (time only, temperature only, either, or neither) generates an alarm condition. For storage of general system data or time/temperature data logging, the device features 32 bytes of SRAM. Applications for the device include networking equipment, industrial equipment, office equipment, thermal data loggers, or any microprocessor-based, thermally sensitive system.