MCP79412-I/MS

Real Time Clock Overview

The MCP79412-I/MS is a battery-backed I2C Real-Time Clock/Calendar (RTCC) IC manufactured by Microchip Technology in an 8-lead MSOP package. It tracks time using internal counters for hours, minutes, seconds, day of week, date, month, and year, with leap year compensation through 2399. The device features on-chip digital trimming for oscillator calibration, dual programmable alarms, and a versatile multifunction output pin. It includes 64 bytes of battery-backed SRAM, 1 Kbit of EEPROM, and a protected 64-bit EEPROM area preprogrammed with an EUI-64 MAC address. Operating voltages range from 1.8V to 5.5V for VCC and 1.3V to 5.5V for VBAT, with typical timekeeping currents of 1.2µA at 3.3V.

Real Time Clock Feature Summary

• Real-Time Clock/Calendar with 12/24-hour modes and leap year compensation to 2399
• On-chip digital trimming with ±1 ppm resolution and ±129 ppm range
• Protected EEPROM area containing factory-programmed EUI-64™ MAC address
• Automatic power-fail switchover with timestamp logging for backup events

Real Time Clock Applications

• Systems requiring precise timekeeping with low-power battery backup
• Devices needing unique hardware identification via EUI-64 addresses
• Industrial equipment operating within -40°C to +85°C temperature ranges

Real Time Clock Procurement Notes

Verify the specific suffix 'I/MS' corresponds to the Industrial temperature range (-40°C to +85°C) and MSOP-8 package. Confirm that the EUI-64 protected memory is required, as the MCP79410 lacks this feature and the MCP79411 uses EUI-48. Ensure the design supports the I2C interface timing requirements specified in the datasheet.

Real Time Clock Selection Notes

Select the MCP79412 when a unique 64-bit identifier is necessary, distinguishing it from the MCP79410 (unprogrammed) and MCP79411 (EUI-48). Choose the MSOP package for space-constrained surface-mount applications. Ensure the external crystal load capacitance matches the 6-9 pF optimization range or calculate appropriate external capacitors.

Real Time Clock Part Context

This component belongs to the MCP7941X family of battery-backed RTCCs. The MCP79412 variant is specifically distinguished by its integrated EUI-64™ MAC address in the protected EEPROM section. Other family members include the MCP79410 (no ID) and MCP79411 (EUI-48), all sharing similar timekeeping and memory architectures but differing in the protected memory content.

Real Time Clock Replacement Considerations

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