1338C-31SRI

Overview

The Renesas 1338C-31SRI is a Real-Time Clock (RTC) integrated circuit housed in a 16-SOIC package. It features an embedded crystal oscillator, eliminating the need for external timing components. The device supports I²C serial interface communication and provides timekeeping functions including seconds, minutes, hours, day of the week, date, month, and year with leap-year compensation up to 2100. It operates within a supply voltage range of 3.3V to 5.5V and is rated for industrial temperatures from -40°C to +85°C.

Feature Summary

• Integrated Crystal Oscillator: Built-in crystal removes requirement for external resonator components.
• I²C Interface: Serial communication via two-wire bus for system integration.
• Leap-Year Compensation: Automatic adjustment for leap years through 2100.
• Battery Backup: Supports secondary battery input for continuous timekeeping during main power loss.

Applications

• Industrial control systems requiring precise time synchronization
• Data logging equipment needing accurate timestamping
• Embedded consumer electronics with real-time clock requirements

Procurement Notes

Verify component authenticity through authorized distributors due to potential counterfeit risks. Confirm RoHS compliance status as specifications may vary by manufacturing batch. Check for End-of-Life (EOL) notifications or Product Change Notices (PCN) that may affect long-term availability or pin compatibility. Ensure moisture sensitivity level (MSL) handling procedures are followed during assembly.

Selection Notes

Select this model when board space constraints prohibit external crystals. Compare against the 1339C series if alarm functions or square wave outputs are required, as the 1338C lacks these specific features. Verify voltage compatibility between the 3.3V–5.5V operating range and the target system's logic levels. Consider the 16-SOIC package dimensions for PCB layout planning.

Part Context

This component belongs to the IDT/Renesas 1338/1339C family of RTCs. It serves as a cost-effective alternative to discrete RTC solutions by integrating the crystal oscillator. It is functionally similar to the 1338D series but differs in packaging and specific feature sets such as alarm capabilities found in the 1339C variant.

Replacement Considerations

Direct pin-to-pin replacements include the 1338D-31DVGI (different package) or 1339C-31SRI (if alarm features are acceptable). Verify that the substitute part maintains the same I²C address and register map compatibility for seamless firmware migration.