Real-Time Clocks/Calendars (RTCCs)

Microchip’s portfolio of MCP794x and MCP795x  RTCCs offer low-cost system timekeeping solutions that are highly integrated with a usable amount of non-volatile memory. They offer a combination of features that are very effective when operating within a single battery backed clock device. RTTCs track time with resolutions as small as 1/100th of a second and issue alarms on a wide variety of time conditions. They maintain accurate time through system shutdowns by automatically switching over to an external battery back-up source. RTCCs are designed to operate using a 32.768 kHz quartz crystal and can digitally compensate for frequency variance caused by crystal tolerance and temperature. Microchip RTCCs have an I²C or SPI interface for configuration, reading, and writing the time. Additionally, alarm interrupt requests, square wave output, and system reset control signals are available on dedicated pins.

Microchip’s RTCCs are available with a range of internal memories including battery-backed SRAM, non-volatile EEPROM, and an additional area of protected EEPROM. The protected EEPROM area is only writable after the RTCC receives an unlock sequence and is available pre-programmed with unique EUI-48™ or EUI-64™ MAC address.  With both I²C and SPI RTCCs available, various applications can be supported at a price that is lower than competitive devices with fewer features and lower performance.

Features
Innovative Peripherals Battery switchover with a power fail time stamp Wide digital trimming range Watchdog timer with dual retriggers Event detect inputs with a programmable debounce Unique ID with a user unlock		Easy to Implement I2C and SPI interfaces Industry-standard pinouts I2C: 8-pins SPI: 14-pins Microchip standard development boards
Three Memory Options SRAM EEPROM Unique ID / MAC address