MCP795W21T-I/SL

Real Time Clock Overview

The MCP795W21T-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 64 bytes of SRAM, 2 Kbits of EEPROM, and a protected 128-bit area preprogrammed with an EUI-48 MAC address. Key features include dual programmable alarms, a watchdog timer, event detection modules, and automatic power-fail timestamping.

Real Time Clock Feature Summary

• Integrated RTCC with leap year compensation through 2399 and digital trimming for ±259 ppm accuracy
• Includes 64-byte battery-backed SRAM and 2 Kbit EEPROM with software write protection
• Features dual configurable event detect modules for high-speed pulse counting and low-speed switch debouncing
• Contains a dedicated Watchdog Timer output pin and two alarm outputs assignable to interrupt lines

Real Time Clock Applications

• Portable consumer electronics requiring accurate timekeeping during power loss
• Industrial systems utilizing the watchdog timer for application robustness
• Networked devices leveraging the preprogrammed EUI-48 MAC address for identification

Real Time Clock Procurement Notes

Verify that the ordering suffix 'T' corresponds to tape-and-reel packaging as specified in the manufacturer's documentation. Confirm the 'I' designation indicates the industrial temperature range (-40°C to +85°C). Ensure the 'SL' package type matches the required 14-lead TSSOP footprint for the PCB layout.

Real Time Clock Selection Notes

Select this component when an SPI interface is preferred over I2C for system integration. The MCP795W21 variant is appropriate for designs requiring 2 Kbits of non-volatile storage and a unique hardware identifier. Consider the integrated watchdog and event detection capabilities if external logic components need to be minimized.

Real Time Clock Part Context

This part belongs to the MCP795WXX family of compact, 10-pin RTCCs designed to reduce overall component count. It shares functional similarities with the larger 14-pin MCP795-WXX series but offers a more space-efficient solution for handheld and wireless markets.

Real Time Clock Replacement Considerations

The MCP795W21T-I/ST serves as a direct alternative offering identical electrical specifications and functionality, differing only in the tube packaging format instead of tape-and-reel.