MCP795B22T-I/ST

Real Time Clock Overview

The MCP795B22T-I/ST is a low-power Real-Time Clock/Calendar (RTCC) manufactured by Microchip Technology. It features an integrated 32 kHz boot-up clock output at power-up, distinguishing it from the W-series variants. The device operates within a wide voltage range of 1.8V to 5.5V on VCC and supports battery backup down to 1.3V. Key specifications include a 10 MHz SPI interface speed, 64 bytes of battery-backed SRAM, and 2 Kbit of EEPROM with software write protection. It includes digital trimming for accuracy, dual programmable alarms, and event detection capabilities.

Real Time Clock Feature Summary

• Integrated 32 kHz Boot-up Clock Output at Power-Up
• 10 MHz SPI Interface Speed
• 64-Byte Battery-Backed SRAM and 2 Kbit EEPROM
• On-Chip Digital Trimming/Calibration (±255 PPM range)

Real Time Clock Applications

• Systems requiring millisecond alarm resolution via high-speed SPI
• Applications needing immediate timekeeping availability upon power restoration
• Battery-operated devices requiring automatic switchover between main and backup supplies

Real Time Clock Procurement Notes

Verify that the specific ordering suffix 'I' corresponds to the Industrial temperature range (-40°C to +85°C). Confirm the 'B' designation indicates the presence of the 32 kHz boot-up clock feature, as this differentiates the part from the standard MCP795W series. Ensure the package type matches the required PCB layout for the TSSOP-14 form factor.

Real Time Clock Selection Notes

Select the MCP795B22T-I/ST over the W-series when system startup protocols require an immediate 32 kHz clock signal without waiting for oscillator stabilization. Choose this variant if the application demands a 2 Kbit EEPROM size rather than 1 Kbit. Verify that the host microcontroller supports the required SPI protocol and voltage levels compatible with the 1.8V to 5.5V operating range.

Real Time Clock Part Context

This component belongs to the MCP795WXX/MCP795BXX family of RTCCs. The 'B' prefix specifically denotes devices equipped with a 32 kHz boot-up clock function on the CLKOUT/BOOT pin. The '22' suffix indicates 2 Kbit EEPROM capacity and pre-programmed EUI-64™ Unique ID. The 'T' suffix typically denotes tape and reel packaging, while 'I' specifies the industrial temperature grade.

Real Time Clock Replacement Considerations

The MCP795W22T-I/ST is a functional substitute but lacks the 32 kHz boot-up clock feature. Direct replacements within the same family include other MCP795B22 variants with different package options (e.g., SOIC). Ensure any replacement maintains the 2 Kbit EEPROM size and EUI-64™ ID configuration if those are critical to the design.