MCP79411-I/MS

Real Time Clock Overview

The MCP79411-I/MS is a battery-backed I2C Real-Time Clock/Calendar (RTCC) from Microchip Technology, housed in an 8-lead MSOP package. It operates within a voltage range of 1.8V to 5.5V and supports an industrial temperature range of -40°C to +85°C. The device features a 32.768 kHz oscillator optimized for 6-9 pF crystals, with on-chip digital trimming offering ±1 ppm resolution. Key specifications include a typical timekeeping current of 1.2 µA at 3.3V and backup current of 925 nA at 3.0V. Memory resources consist of 64 bytes of SRAM, 1 Kbit of EEPROM, and a preprogrammed 64-bit EUI-48 MAC address.

Real Time Clock Feature Summary

• Integrated RTCC with dual programmable alarms and power-fail timestamp logging
• 64-byte battery-backed SRAM and 1 Kbit EEPROM with software write-protect
• Preprogrammed 64-bit EUI-48 protected EEPROM area for unique identification
• I2C interface supporting clock rates up to 400 kHz

Real Time Clock Applications

• Systems requiring precise timekeeping with low-power battery backup
• Devices needing secure storage for unique identifiers or MAC addresses
• Applications utilizing I2C communication for data logging and alarm generation

Real Time Clock Procurement Notes

Verify the specific suffix 'I/MS' confirms the Industrial temperature grade (-40°C to +85°C) and the 8-lead MSOP package type. Ensure the part number includes the '11' designation to confirm the inclusion of the preprogrammed EUI-48 address, distinguishing it from the unprogrammed MCP79410 variant.

Real Time Clock Selection Notes

Select this component when an I2C-compatible RTCC with integrated non-volatile memory and a factory-programmed unique ID is required. Consider the MCP79412 if a 64-bit EUI-64 address is needed instead of the 48-bit version. Verify that the application can accommodate the external crystal load capacitors required for the 32.768 kHz oscillator circuit.

Real Time Clock Part Context

This device belongs to the MCP7941X family, which shares functional similarities but differs in memory configuration. The MCP79410 lacks the protected EEPROM area, while the MCP79412 provides a 64-bit EUI-64 address. All variants share the same pinout and core RTCC functionality.

Real Time Clock Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Cross-referencing requires verifying compatible I2C interfaces, voltage ranges, and package dimensions.