MCP7940MT-I/SN

Real Time Clock Overview

The MCP7940MT-I/SN is a Real-Time Clock/Calendar (RTCC) integrated circuit manufactured by Microchip Technology. It operates within an industrial temperature range of -40°C to +85°C and supports a supply voltage from 1.8V to 5.5V. The device features a 2-wire I2C interface with clock rates up to 400 kHz, 64 bytes of SRAM, and dual programmable alarms. Timekeeping current is typically 1.2 µA at 3.3V. It utilizes a 32.768 kHz crystal or external clock input and includes on-chip digital trimming for frequency calibration.

Real Time Clock Feature Summary

• Real-Time Clock/Calendar with leap year compensation through 2399
• On-chip digital trimming with ±1 PPM resolution and ±129 PPM range
• Dual programmable alarms with flexible comparison options
• Versatile multifunction open-drain output pin (MFP)

Real Time Clock Applications

• Microcontroller-based systems requiring precise timekeeping
• Data logging devices needing calendar tracking
• Low-power battery-operated electronics

Real Time Clock Procurement Notes

Verify the package type matches the required footprint, as the MCP7940M series is available in multiple packages including SOIC, MSOP, TSSOP, PDIP, and TDFN. Confirm that the 'I' suffix indicates the industrial temperature range (-40°C to +85°C). Ensure the specific ordering suffix corresponds to the desired tape and reel or cut tape packaging configuration.

Real Time Clock Selection Notes

Select this component when a low-cost I2C RTCC with integrated SRAM is required. It is suitable for applications needing dual alarms and digital frequency trimming. Consider alternative packages such as MSOP or TDFN if space constraints exist, or PDIP for prototyping. Verify compatibility with the system's I2C bus voltage levels.

Real Time Clock Part Context

The MCP7940MT-I/SN belongs to the MCP7940M family of real-time clocks. This family provides a cost-effective solution for timekeeping with user-accessible memory. Other variants in the series include different package types like MSOP and TDFN, as well as automotive-grade versions like the MCP7940NT.

Real Time Clock Replacement Considerations

Direct replacements within the same package and electrical specifications include other MCP7940M variants such as MCP7940M-I/MS, MCP7940M-I/SN, or MCP7940M-I/ST. For automotive applications, the MCP7940NT series may be considered if AEC-Q100 qualification is required.