The PCF2129AT/2518 is a 32-bit Real-Time Clock (RTC) IC produced by NXP Semiconductors. This RTC is specially designed for automotive applications and includes an integrated digital temperature sensor. The IC is capable of providing an accurate time keeping down to seconds, minutes, and centuries. It supports a wide voltage range (2.0-5.5V), temperature range (-40°C to +125°C), and a variety of communication protocols including I2C, SPI, as well as smooth transfer between different crystal frequencies. It also supports communication between different power domains and is capable of working in 40 kHz and 32.768 kHz temperature-compensated crystal oscillator frequencies. The PCF2129AT/2518 also includes a variety of features to protect against damage from EMI and other environmental conditions.