MCP795B12-I/ST

Real Time Clock Overview

The MCP795B12-I/ST is a low-power Real-Time Clock/Calendar (RTCC) manufactured by Microchip Technology. It features an SPI interface with clock speeds up to 10 MHz and operates within a voltage range of 1.8V to 5.5V on VCC, and 1.3V to 5.5V on VBAT. The device includes 64 bytes of battery-backed SRAM and 1 Kbit of EEPROM memory. Key specifications include a 32 kHz boot-up clock output at power-up, programmable watchdog timer, dual event detect inputs, and automatic battery switchover. It supports industrial temperature ranges from -40°C to +85°C and is available in 14-lead SOIC and TSSOP packages.

Real Time Clock Feature Summary

• Integrated 32 kHz Boot-up Clock Output at Power-up
• 1 Kbit EEPROM with Software Block Write-Protect and 1M Endurance Cycles
• Dual Programmable Alarms with Enhanced Resolution (Tenth/Hundredth Seconds)
• Programmable Watchdog Timer with Dedicated Output Pin

Real Time Clock Applications

• Systems requiring millisecond-level alarm precision
• Applications needing automatic time-stamping during power failures
• Embedded devices utilizing external event detection via EVHS/EVLS pins

Real Time Clock Procurement Notes

Verify the specific ordering suffix for package type (SOIC or TSSOP) as both are supported. Confirm the presence of the preprogrammed EUI-64 MAC address if required for network identification. Ensure the design accounts for the 32 kHz external crystal and load capacitors necessary for oscillator operation.

Real Time Clock Selection Notes

Select this model over the W-series variants specifically when a 32 kHz clock signal is needed immediately upon power-up. The B-series designation indicates the inclusion of the boot-up clock feature. Ensure the application requires the 1 Kbit EEPROM capacity; larger capacities are available in other family members like the MCP795B22.

Real Time Clock Part Context

This component belongs to the MCP795WXX/MCP795BXX family of SPI Real-Time Clocks. The 'B' prefix distinguishes it from the 'W' series by providing a 32 kHz boot-up clock function. The '12' suffix denotes 1 Kbit EEPROM storage and preprogrammed EUI-64 unique ID capabilities.

Real Time Clock Replacement Considerations

Direct functional substitutes within the same family include MCP795B11 (EUI-48 ID) and MCP795B22 (2 Kbit EEPROM). Cross-family replacements such as MCP7940N require interface changes from SPI to I2C.