MCP79410T-I/MS

Real Time Clock Overview

The MCP79410T-I/MS is a battery-backed I2C Real-Time Clock/Calendar (RTCC) integrated circuit manufactured by 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 supply voltage range of 1.8V to 5.5V and features low power consumption, drawing 1.2 µA at 3.3V during operation. It includes 64 bytes of battery-backed SRAM, 1 Kbit of EEPROM, and an unprogrammed 64-bit protected EEPROM area. The IC communicates via an I2C interface supporting clock rates up to 400 kHz and is housed in an 8-lead MSOP package.

Real Time Clock Feature Summary

• Integrated Real-Time Clock/Calendar with dual programmable alarms and versatile multifunction output pin.
• On-chip digital trimming/calibration with ±1 ppm resolution and ±129 ppm range for frequency adjustment.
• Includes 64-byte battery-backed SRAM, 1 Kbit EEPROM with software write-protect, and 64-bit protected EEPROM.
• Automatic switchover to backup supply (VBAT) with power-fail timestamp logging capabilities.

Real Time Clock Applications

• Electronic watches and wearable devices requiring precise timekeeping.
• Industrial systems needing data retention and timestamping during power failures.
• Embedded controllers utilizing I2C communication for calendar and alarm functions.

Real Time Clock Procurement Notes

Verify the ordering suffix 'T-I/MS' corresponds to the tape and reel packaging format and industrial temperature grade (-40°C to +85°C). Confirm that the specific variant lacks pre-programmed EUI addresses, distinguishing it from the MCP79411 and MCP79412 models which contain factory-set MAC addresses.

Real Time Clock Selection Notes

Select this component when an unprogrammed protected EEPROM area is required for custom unique ID storage. Ensure the design accommodates external load capacitors for the 32.768 kHz crystal, as the device is optimized for crystals with 6-9 pF load capacitance. Verify I2C bus pull-up resistor values align with the desired clock speed and supply voltage.

Real Time Clock Part Context

This part belongs to the MCP7941X family, which also includes the MCP79411 and MCP79412. While functionally identical regarding timekeeping and memory architecture, the MCP79411 and MCP79412 differ by having factory-programmed EUI-48 and EUI-64 MAC addresses in their protected EEPROM sections, respectively. The MCP79410 specifically offers an unprogrammed protected area for user-defined data.

Real Time Clock Replacement Considerations

The MCP79411T-I/MS and MCP79412T-I/MS are direct functional substitutes within the same package. Note that these replacements contain pre-programmed EUI addresses in the protected EEPROM, whereas the MCP79410 does not. Other packages such as SOIC or TSSOP variants may require schematic adjustments for pin compatibility if form factor changes are acceptable.