RX-8731LC:B3 PURE SN

Real Time Clock Overview

The RX-8731LC:B3 PURE SN is a Real Time Clock (RTC) module manufactured by EPSON. It integrates a built-in frequency-adjusted 32.768 kHz crystal unit and communicates via an I2C-Bus interface supporting high-speed specifications up to 400 kHz. The device operates within a power voltage range of 1.7 V to 5.5 V, with a wide timekeeping voltage range of 1.3 V to 5.5 V. Key features include a 10-byte (80-bit) built-in EEPROM and a 6-byte (48-bit) Unique ID-ROM. It provides programmable I/O ports and various interrupt functions, including alarm, timer, and update interrupts.

Real Time Clock Feature Summary

• Built-in 10-byte (80-bit) EEPROM and 6-byte (48-bit) Unique ID-ROM
• I2C-Bus interface compatible with high-speed specifications (400 kHz)
• Low backup current consumption: typical 0.35 µA at 3 V
• 32.768 kHz frequency output function with CMOS output control

Real Time Clock Applications

• Car Multimedia systems
• Body Electronics
• Remote Keyless Entry systems
• Engine Control Units
• Air Bag systems
• Electronic Stability Control (ESC)

Real Time Clock Procurement Notes

Verify the component status as End-of-Life (EOL). Confirm that no adhesive glue should be applied to the LC-package after soldering, as invasion between the circuit board side and glass side may cause cracks due to thermal expansion, potentially stopping crystal oscillation.

Real Time Clock Selection Notes

Select this model for applications requiring integrated memory and unique identification alongside timekeeping. Ensure the design accommodates the 12-VSOJ package dimensions and strictly avoids gluing near the package glass backside to prevent mechanical failure during thermal cycling.

Real Time Clock Part Context

This component belongs to the RX-8731LC series of real-time clock modules. It is designed for automotive applications such as car multimedia, body electronics, remote keyless entry, engine control units, air bags, and ESC systems, meeting ISO/TS16949 certification standards.

Real Time Clock Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material.