MCP7940NT-E/SNVAO

Real Time Clock Overview

The MCP7940NT-E/SNVAO is an automotive-grade Real-Time Clock/Calendar (RTCC) manufactured by Microchip Technology. It operates within a supply voltage range of 1.8V to 5.5V and supports backup voltages from 1.3V to 5.5V. The device features a two-wire I2C interface with clock rates up to 400 kHz, 64 bytes of battery-backed SRAM, and dual programmable alarms. Timekeeping accuracy is supported by on-chip digital trimming with ±1 PPM resolution over a ±129 PPM range. It functions in the extended industrial temperature range of -40°C to +125°C and is housed in an 8-lead SOIC package.

Real Time Clock Feature Summary

• AEC-Q100 qualified for automotive applications
• On-chip digital trimming for frequency calibration
• Automatic switchover to battery backup with power-fail time-stamping
• Dual programmable alarms and versatile multifunction output pin

Real Time Clock Applications

• Automotive telematics systems
• Industrial data logging equipment
• Smart metering devices

Real Time Clock Procurement Notes

Verify that the VAO suffix indicates specific automotive qualification or packaging variations as defined by Microchip. Confirm the package type matches the required PCB footprint, specifically the 8-SOIC form factor. Ensure compatibility with the target system's I2C bus voltage levels and pull-up requirements.

Real Time Clock Selection Notes

Select this component when extended temperature operation up to 125°C is required. The E-temp rating distinguishes it from the standard Industrial (-40°C to +85°C) variants. Ensure the application utilizes a 32.768 kHz crystal with a load capacitance between 6 pF and 9 pF for optimal oscillator performance.

Real Time Clock Part Context

This part belongs to the MCP7940N family of battery-backed I2C RTCCs with SRAM. The 'E' designation specifies the Extended temperature range, while 'SN' denotes the 8-SOIC package. The 'T' indicates tape and reel packaging, and 'VAO' typically signifies automotive-specific ordering or qualification details.

Real Time Clock Replacement Considerations

Standard replacements include MCP7940NT-I/SN for industrial temperature ranges. For different packages, consider MCP7940NT-E/ST (TSSOP) or MCP7940NT-E/MSOP. Verify that any substitute maintains AEC-Q100 compliance if automotive qualification is mandatory.