MCP79410-I/ST

Real Time Clock Overview

The MCP79410-I/ST is a battery-backed I2C Real-Time Clock/Calendar (RTCC) from Microchip Technology, housed in an 8-lead TSSOP 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 operates on a primary supply of 1.8V to 5.5V and a backup supply of 1.3V to 5.5V. Typical timekeeping current is 1.2 µA at 3.3V on VCC and 925 nA at 3.0V on VBAT. It features 64 bytes of SRAM, 1 Kbit of EEPROM, and unprogrammed protected EEPROM.

Real Time Clock Feature Summary

• I2C compatible serial interface supporting clock rates up to 400 kHz
• On-chip digital trimming with ±1 ppm resolution and ±129 ppm range
• Dual programmable alarms with flexible comparison options
• Versatile multifunction output pin configurable as alarm, square wave, or general purpose output

Real Time Clock Applications

• Electronic devices requiring accurate timekeeping and calendar functions
• Systems needing non-volatile data storage via integrated SRAM and EEPROM
• Applications utilizing power-fail timestamp logging for event tracking

Real Time Clock Procurement Notes

Verify the specific suffix 'I/ST' corresponds to the Industrial temperature range (-40°C to +85°C) and TSSOP-8 package. Confirm that the MCP79410 variant contains unprogrammed protected EEPROM, unlike the MCP79411 (EUI-48) or MCP79412 (EUI-64). Ensure external load capacitors are selected to match the crystal's specified load capacitance of 6-9 pF for optimal oscillator performance.

Real Time Clock Selection Notes

Select the MCP79410 when EUI-48 or EUI-64 MAC addresses are not required, as these are pre-programmed only in the MCP79411 and MCP79412 variants. Ensure the application voltage remains within the 1.8V to 5.5V operating range. For low-power designs, utilize the automatic switchover feature between VCC and VBAT to maintain time and SRAM contents during primary power loss.

Real Time Clock Part Context

The MCP79410 is part of the MCP7941X family, which includes the MCP79411 and MCP79412. These devices share identical functionality regarding timekeeping, memory, and interfaces. The primary distinction lies in the protected EEPROM section: the MCP79410 has unprogrammed protected memory, while the MCP79411 and MCP79412 come pre-programmed with EUI-48 and EUI-64 addresses, respectively.

Real Time Clock Replacement Considerations

Publicly confirmed substitute part numbers for the MCP79410-I/ST are not available in the provided documentation. Designers should verify compatibility with alternative RTCCs based on I2C interface, pinout, and memory specifications.