The PCF2127AT/2Y is an accurate Real Time Clock with an integrated temperature compensated crystal (Xtal) oscillator (TCXO) and a 32.768kHz quartz crystal optimized for very high accuracy and very low power consumption. This has 512bytes of general-purpose static RAM, a selectable I?C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function and a timestamp function.

• Timestamp function with interrupt capability
• 3 Line SPI-bus with separate data input and output
• Battery backup input pin and switch-over circuitry
• Extra power fail detection function with input and output pins
• Oscillator stop detection function
• Open-drain interrupt output
• Programmable countdown timer with interrupt