MCP795B20T-I/ST

Real Time Clock Overview

The MCP795B20T-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, supporting industrial temperature ranges from -40°C to +85°C. The device includes 64 bytes of battery-backed SRAM and 2 Kbits of EEPROM memory. Key electrical parameters include a VCC operating range of 1.8V to 5.5V and a VBAT range of 1.3V to 5.5V. Standby current is less than 1 µA at 3V, while timekeeping current via backup supply is under 700 nA at 1.8V. The 'B' suffix indicates support for a 32 kHz boot-up clock output.

Real Time Clock Feature Summary

• Integrated Real-Time Clock/Calendar with digital trimming calibration (+/- 255 PPM).
• 2 Kbit EEPROM and 64-byte battery-backed SRAM with software write-protect.
• Programmable Watchdog Timer and dual configurable Event Detect inputs (EVHS/EVLS).
• Automatic battery switchover with power-fail time-stamping capabilities.

Real Time Clock Applications

• Systems requiring millisecond-level alarm precision via high-speed SPI.
• Applications needing automatic backup switching and power-loss logging.
• Devices utilizing external event detection for hardware interrupts.

Real Time Clock Procurement Notes

Verify the ordering suffix 'T' corresponds to tape-and-reel packaging in official documentation. Confirm the specific package type (SOIC or TSSOP) required for the design. Ensure the Industrial temperature grade (-40°C to +85°C) meets environmental specifications. Cross-reference the 2 Kbit EEPROM capacity against alternative models if different memory sizes are needed.

Real Time Clock Selection Notes

Select this model over the MCP795W20 variant specifically for the 32 kHz boot-up clock feature on the CLKOUT/BOOT pin. Choose based on the requirement for 2 Kbit non-volatile storage rather than 1 Kbit options. Ensure the system supports SPI communication protocols. Verify that the 1.8V to 5.5V voltage range aligns with the main power supply rails.

Real Time Clock Part Context

This component belongs to the MCP795WXX/MCP795BXX family of SPI Real-Time Clocks. The 'B' designation distinguishes it from the 'W' series by providing a 32 kHz clock output at power-up. The '20' identifier specifies 2 Kbit EEPROM and blank Unique ID storage. The 'I' denotes the Industrial temperature rating, and 'ST' indicates surface-mount packaging.

Real Time Clock Replacement Considerations

MCP795W20T-I/ST: Identical functionality except lacks the 32 kHz boot-up clock feature. MCP795B10T-I/ST: Similar features but contains only 1 Kbit EEPROM instead of 2 Kbit.