M41T81SM6F

Real Time Clock Overview

The M41T81SM6F is a low-power serial real-time clock (RTC) IC manufactured by STMicroelectronics. It features an I2C interface and operates within a supply voltage range of 2.7V to 5.5V, with battery backup support from 2V to 3.5V. The device includes a built-in power sense circuit for automatic switchover to a lithium button cell during power failures. Key specifications include a maximum timing current of 100µA at 2.7V–5.5V and an operating temperature range of -40°C to +85°C. It is housed in an 8-SOIC package.

Real Time Clock Feature Summary

• I2C bus interface supporting 400 kHz protocol
• Automatic power failure detection and battery switchover
• Built-in 32.768 kHz oscillator with integrated load capacitance
• Alarm interrupts, watchdog timer, and programmable square wave output

Real Time Clock Applications

• Smart grid distribution systems
• Smart meters
• Industrial monitoring equipment

Real Time Clock Procurement Notes

Verify the specific suffix 'M6F' against the official STMicroelectronics datasheet to confirm pinout and electrical characteristics match the design requirements. Confirm RoHS3 compliance status as indicated in distributor listings. Check for moisture sensitivity level (MSL 1) handling requirements during assembly.

Real Time Clock Selection Notes

Select this component for designs requiring industrial temperature stability (-40°C to +85°C) and low standby current. Ensure the system supports I2C communication. For applications requiring lower voltage operation below 2.7V, consider alternative variants such as the M41T81S or M41T81R series.

Real Time Clock Part Context

The M41T81SM6F belongs to the M41T81M family of serial RTCs. It is part of a broader portfolio that includes variants like the M41T81S and M41T83, which offer different voltage ranges or additional features such as embedded crystals. This specific model utilizes an external crystal configuration.

Real Time Clock Replacement Considerations

The M41T81S is explicitly recommended over the M41T81 for new designs. Verify compatibility with other M41T81 family members if substituting, noting potential differences in minimum operating voltage and feature sets.