Analog Devices currently has two ±5ppm accuracy RTCs with embedded-MEMs resonators. The DS3231M and DS3232M specify ±5ppm accuracy over the full industrial temperature range and over the life of the product. Only this product family includes drift and aging in the accuracy specification. The resonator is mounted on the RTC IC and is wire bonded to the device. Designs with integrated crystals mount the resonator next to the IC. Analog Devices' products are available in a small 8-pin package. There is however, a package option that is footprint-compatible with the DS3231S, Analog Devices' precision RTC product with an embedded crystal in a 16-pin SOIC. A precision temperature-compensated voltage reference and comparator circuit monitors the status of VCC to detect power failures, to provide a reset output, and to automatically switch to the backup supply when necessary. Additionally, the RST pin is monitored as a pushbutton input for generating a microprocessor reset. The DS3232M adds 236-bytes of user battery-backed SRAM to the RTC. The ruggedness of MEMs-based design and low battery-backed power of the DS323xM products have uses in many industrial, automotive, and portable applications that require high timekeeping precision over all operating conditions.