MCP79402-I/MS

Real Time Clock Overview

The MCP79402-I/MS is a battery-backed I2C Real-Time Clock/Calendar (RTCC) with SRAM and protected EEPROM. It operates within a voltage range of 1.8V to 5.5V, consuming 1.2 µA at 3.3V. The device features dual programmable alarms, a multifunction pin for square wave output, and on-chip digital trimming with ±1 ppm resolution. It includes 64 bytes of user-accessible SRAM and an 8-byte protected EEPROM preprogrammed with an EUI-64 MAC address. The industrial temperature range spans from -40°C to +85°C.

Real Time Clock Feature Summary

• Real-Time Clock/Calendar with leap year compensation up to 2399
• 64-bit Protected EEPROM containing a factory-programmed EUI-64™ MAC address
• Dual programmable alarms with flexible comparison options
• On-chip digital trimming/calibration with ±129 ppm range

Real Time Clock Applications

• Systems requiring unique hardware identification via EUI-64
• Battery-powered devices needing low standby current
• Industrial equipment operating in wide temperature ranges
• Data logging applications utilizing power-fail timestamps

Real Time Clock Procurement Notes

Verify the specific suffix 'I/MS' corresponds to the Industrial temperature grade (-40°C to +85°C) and the MSOP package type. Confirm that the EUI-64™ MAC address programming requirement matches the MCP79402 variant rather than the MCP79400 or MCP79401.

Real Time Clock Selection Notes

Select this component when an integrated solution for timekeeping, non-volatile memory, and unique device identification is required. Ensure the application supports I2C communication speeds up to 400 kHz. Verify that the external crystal load capacitance requirements (6-9 pF) align with the available crystal components.

Real Time Clock Part Context

This part belongs to the MCP7940X family, which shares identical core functionality but differs in EEPROM content. The MCP79400 has unprogrammed EEPROM, the MCP79401 contains an EUI-48™ address, and the MCP79402 contains an EUI-64™ address. All variants support the same RTCC and SRAM features.

Real Time Clock Replacement Considerations

The MCP79400-I/MS and MCP79401-I/MS are functional substitutes if the specific EUI-64™ MAC address is not required by the system design.