The PCF8583T/5.518 part of NXP is an low power Serial Real Time Clock (RTC) manufactured by NXP Semiconductors. It provides the accurate timekeeping necessary for remotely monitored or automated systems. The device is a low power Real-Time Clock (RTC) and calendar, providing information like the year, month, day, hour, minute, second and day-of-week. The device has a programmable periodic interrupt output as well as an external input and output individually programmable power management, which helps in further reducing power consumption. The PCF8583T/5.518 is accurate to within ±3 minutes per month at +25°C and has a temperature range of -40 to +85°C. It is available in an SO16 package.