MCP79411T-I/ST

Real Time Clock Overview

The MCP79411T-I/ST is a battery-backed I2C Real-Time Clock/Calendar (RTCC) from Microchip Technology. 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 operates on a 32.768 kHz crystal or external clock input and features digital trimming for frequency calibration. It includes 64 bytes of battery-backed SRAM, 1 Kbit of EEPROM, and a protected 64-bit EUI-48 MAC address area. The part supports an I2C interface up to 400 kHz, dual programmable alarms, and automatic switchover between VCC and VBAT supplies.

Real Time Clock Feature Summary

• Integrated Real-Time Clock/Calendar with 64-byte battery-backed SRAM and 1 Kbit EEPROM
• Pre-programmed 64-bit EUI-48 MAC address in protected EEPROM
• Dual programmable alarms and versatile multifunction output pin (MFP)
• Low-power operation: 1.2 µA typical at 3.3V; backup current 925 nA at 3.0V

Real Time Clock Applications

• Battery-powered portable electronics requiring accurate timekeeping
• Systems needing non-volatile data storage with unique device identification
• Industrial control systems operating within -40°C to +85°C temperature range

Real Time Clock Procurement Notes

Verify the 'I' suffix indicates the industrial temperature range (-40°C to +85°C) and the '/ST' suffix denotes the TSSOP package. Confirm that the specific revision matches the required EUI-48 programming status. Ensure compatibility with the target I2C bus voltage levels and pull-up resistor requirements for reliable communication.

Real Time Clock Selection Notes

Select this component when a compact RTCC with integrated memory and a factory-assigned EUI-48 address is required. Compare against MCP79410 if no unique ID is needed, or MCP79412 if EUI-64 addressing is preferred. Ensure the application can accommodate the necessary external load capacitors for the 32.768 kHz crystal oscillator circuit.

Real Time Clock Part Context

This part belongs to the MCP7941X family of battery-backed I2C RTCCs. It shares the same core functionality as the MCP79410 and MCP79412 but is distinguished by its pre-programmed EUI-48 MAC address in the protected EEPROM section. The 'T' in the model number typically indicates tape-and-reel packaging for automated assembly.

Real Time Clock Replacement Considerations

The MCP79410T-I/ST is a functional substitute if the EUI-48 address is not required. The MCP79412T-I/ST serves as a replacement if EUI-64 addressing is needed instead. Verify that any cross-model substitution maintains compatibility with the existing software drivers and memory map configurations.