MCP79402T-I/SN

Real Time Clock Overview

The MCP79402T-I/SN is a battery-backed I2C Real-Time Clock/Calendar (RTCC) with SRAM and protected EEPROM. It tracks time using internal counters for hours, minutes, seconds, day of week, date, month, and year, supporting 12/24-hour modes and leap year compensation to 2399. The device operates on a primary supply of 1.8V to 5.5V and a backup supply of 1.3V to 5.5V. Typical timekeeping current is 1.2 µA at 3.3V VCC and 925 nA at 3.0V VBAT. It features 64 bytes of battery-backed SRAM and an 8-byte protected EEPROM preprogrammed with an EUI-64 MAC address.

Real Time Clock Feature Summary

• Integrated RTCC with dual programmable alarms and power-fail timestamp logging
• On-chip digital trimming for oscillator calibration with ±1 ppm resolution
• Versatile multifunction pin (MFP) configurable as alarm output, square wave generator, or general purpose output
• Protected EEPROM area containing factory-programmed EUI-64™ MAC address

Real Time Clock Applications

• Systems requiring precise timekeeping with automatic battery switchover
• Devices needing persistent storage for unique identifiers via EUI-64 EEPROM
• Applications utilizing digital frequency trimming for crystal tolerance compensation

Real Time Clock Procurement Notes

Verify the specific suffix 'SN' corresponds to the 8-pin SOIC package when sourcing. Confirm the 'I' designation indicates the industrial temperature range of -40°C to +85°C. Ensure the part number includes the 'T' prefix if reel packaging is required rather than cut tape.

Real Time Clock Selection Notes

Select this model over the MCP79400 or MCP79401 specifically for the requirement of a preprogrammed EUI-64™ MAC address in the protected EEPROM. The MCP79400 contains unprogrammed EEPROM, while the MCP79401 provides an EUI-48™ address. All variants share identical timekeeping and memory specifications otherwise.

Real Time Clock Part Context

This component belongs to the MCP7940X family of battery-backed RTCCs manufactured by Microchip Technology. The family shares common architecture including I2C interface, SRAM, and alarm modules. The MCP79402 variant is distinguished by its factory-programmed EUI-64™ node address stored in the protected EEPROM section.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.