MCP795W21-I/SL

Real Time Clock Overview

The MCP795W21-I/SL is a battery-backed SPI Real-Time Clock/Calendar (RTCC) manufactured by Microchip Technology. It operates within an industrial temperature range of -40°C to +85°C and supports supply voltages from 1.8V to 3.6V. The device integrates 2 Kbit EEPROM, 64 bytes of battery-backed SRAM, and a 128-bit protected EEPROM area preprogrammed with an EUI-48 MAC address. Key features include dual programmable alarms, a watchdog timer, event detection modules, and automatic switchover between primary and backup power supplies.

Real Time Clock Feature Summary

• Real-Time Clock/Calendar tracking hundredths of seconds through year, with leap year compensation to 2399.
• Integrated memory comprising 2 Kbit EEPROM, 64-byte SRAM, and 128-bit protected EEPROM with EUI-48 address.
• Dual Event Detect Modules for high-speed pulse counting and low-speed switch debouncing.
• Programmable Watchdog Timer with dedicated output pin and alarm assignment capabilities.

Real Time Clock Applications

• Smart energy devices such as thermostats and power meters.
• Home appliances including coffee makers and microwave ovens.
• Automotive dashboard controls and GPS systems.
• Consumer electronics like office equipment and video systems.

Real Time Clock Procurement Notes

Verify the ordering suffix 'I/SL' corresponds to the Industrial temperature grade (-40°C to +85°C) and the 14-lead TSSOP package. Confirm that the specific part number includes the EUI-48 protected EEPROM configuration. Ensure compatibility with the required SPI interface speed and voltage levels before procurement.

Real Time Clock Selection Notes

Select this component when an SPI interface is preferred over I2C for RTCC functionality. Choose the MCP795W21 variant specifically for its 2 Kbit EEPROM capacity compared to the 1 Kbit option in the W1X series. The integrated EUI-48 address simplifies network identification requirements without additional external components.

Real Time Clock Part Context

This device belongs to the MCP795WXX family of standalone RTCCs. It shares functional similarities with the MCP795BXX series but utilizes an SPI interface instead of I2C. The 'W21' designation indicates the 2 Kbit EEPROM size and EUI-48 protected memory configuration within the broader product line.

Real Time Clock Replacement Considerations

The MCP795W21-I/ST serves as a direct package alternative using the 14-lead SOIC format. For applications requiring I2C connectivity, the MCP7940N series offers comparable timekeeping features with different interface protocols. Verify pinout compatibility when substituting packages.