MCP79411T-I/MS

Real Time Clock Overview

The MCP79411T-I/MS is a battery-backed I2C Real-Time Clock/Calendar (RTCC) from Microchip Technology, part of the MCP7941X family. It tracks time using internal counters for hours, minutes, seconds, day of week, date, month, and year, with leap year compensation to 2399. The device features 64 bytes of battery-backed SRAM, 1 Kbit of EEPROM, and a preprogrammed 64-bit EUI-48 MAC address in protected EEPROM. It operates on a supply voltage of 1.8V to 5.5V with a backup range of 1.3V to 5.5V. Typical timekeeping current is 1.2 µA at 3.3V (VCC) and 925 nA at 3.0V (VBAT).

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.
• Preprogrammed 64-bit EUI-48 MAC address in protected EEPROM area.
• I2C interface supporting clock rates up to 400 kHz.

Real Time Clock Applications

• Systems requiring precise timekeeping with nonvolatile memory for configuration or data storage.
• Devices needing unique hardware identification via preprogrammed EUI-48 addresses.
• Battery-powered applications utilizing automatic switchover between primary and backup supplies.

Real Time Clock Procurement Notes

Verify that the ordering suffix 'T' corresponds to the tape-and-reel packaging format required for automated assembly processes. Confirm the '-I' designation matches the industrial temperature range specifications (-40°C to +85°C) for the target application environment.

Real Time Clock Selection Notes

Select this component when an integrated solution combining RTC functionality, general-purpose SRAM, and EEPROM is required. The MCP79411 variant is specifically chosen over the MCP79410 or MCP79412 if a preprogrammed EUI-48 MAC address is necessary for network identification without custom programming steps.

Real Time Clock Part Context

This part belongs to the MCP7941X series, which includes the MCP79410, MCP79411, and MCP79412. These devices share identical pinouts and core functionalities, differing primarily in the content of their protected EEPROM areas: unprogrammed (MCP79410), EUI-48 (MCP79411), and EUI-64 (MCP79412).

Real Time Clock Replacement Considerations

The MCP79410T-I/MS and MCP79412T-I/MS are direct pin-compatible replacements within the same package. Substitution requires verifying if the specific protected EEPROM content (EUI-48 vs. none vs. EUI-64) meets the system requirements.