1338AC-18SRGI

Overview

The Renesas 1338AC-18SRGI is an active real-time clock (RTC) featuring battery-backed non-volatile RAM. It operates within a supply voltage range of 2.0V to 5.5V and supports I²C serial communication. The device includes a dedicated 32.768kHz crystal oscillator for timekeeping accuracy. It provides 128 bytes of non-volatile RAM accessible via the I²C interface, allowing data retention during power loss when backed by an external battery. The component is housed in an 8-pin SOIC package with a lead count of 8.

Feature Summary

• Active RTC with integrated 32.768kHz oscillator
• 128 bytes of battery-backed non-volatile RAM
• I²C serial interface for register access
• Wide operating voltage range: 2.0V to 5.5V

Applications

• Data logging systems requiring persistent timestamp storage
• Industrial equipment needing accurate timekeeping during power cycles
• Consumer electronics with calendar and alarm functions

Procurement Notes

Verify the specific suffix 'SRGI' against official Renesas documentation to confirm package type and temperature grade. Ensure compatibility with system I²C bus voltage levels. Confirm battery backup circuit requirements for the non-volatile RAM section. Check for end-of-life notices or alternative part recommendations from the manufacturer before finalizing procurement.

Selection Notes

Select this component when both precise timekeeping and small-scale data storage are required in a single IC. The 128-byte RAM capacity suits applications storing limited configuration data or event logs alongside timestamps. Verify that the I²C address matches the system design constraints. Consider the 8-pin SOIC package dimensions for PCB layout feasibility compared to smaller alternatives.

Part Context

The 1338 series represents Renesas' standard line of real-time clocks with non-volatile memory capabilities. This specific model integrates the RTC logic and memory controller on a single die, reducing external component count. It is designed for general-purpose embedded applications where cost-effective time and data retention is critical without using separate EEPROMs.

Replacement Considerations

Direct pin-to-pin replacements may include other 1338 variants with different suffixes indicating package or temperature changes. Verify functional equivalence regarding RAM size and I²C protocol if substituting with similar RTCs from other manufacturers. Cross-reference datasheets for voltage tolerance and current consumption differences.