RTC-4543SA:A0

Real Time Clock Overview

The RTC-4543SA is a real-time clock module manufactured by Epson Timing, housed in a 14-pin SOP package. It integrates a frequency-adjusted 32.768 kHz crystal unit with an SPI-compatible 3-wire serial interface. The device operates within a power supply voltage range of 2.5 V to 5.5 V and supports a wide timekeeper voltage range from 1.4 V to 5.5 V. Key electrical characteristics include a frequency tolerance of ±23 ppm at +25 °C and maximum current consumption of 3.0 µA at 5 V. It features a 32.768 kHz or 1 Hz output function, full calendar capabilities, and automatic power supply voltage detection.

Real Time Clock Feature Summary

• Integrated 32.768 kHz crystal unit eliminates external frequency adjustment requirements.
• 3-wire serial interface (SPI-compatible) utilizing CE, CLK, WR, and DATA pins.
• Configurable FOUT pin provides selectable 32.768 kHz or 1 Hz CMOS output.
• Automatic low-voltage detection triggers flag recording when VDD drops below 1.7 V.

Real Time Clock Applications

• Automotive body electronics and remote keyless entry systems.
• Car multimedia and navigation system timing references.
• Engine control units (ECU) and driving safety subsystems.
• General electronic equipment requiring precise timekeeping.

Real Time Clock Procurement Notes

Verify the specific ordering suffix for the requested model variant, as suffixes may indicate environmental compliance or packaging differences. Confirm availability status directly with authorized distributors, as production lifecycles for specific RTC modules can change. Ensure the selected part matches the required operating temperature range and voltage specifications for the target application environment.

Real Time Clock Selection Notes

Select this component for designs requiring a compact solution with built-in crystal calibration. The 1.4 V minimum timekeeper voltage allows for extended battery backup operation compared to standard 2.0 V devices. Verify that the host microcontroller supports the 3-wire serial protocol and that the available GPIO pins align with the CE, CLK, WR, and DATA signal requirements.

Real Time Clock Part Context

The RTC-4543SA belongs to the SA series of Epson real-time clock modules, characterized by the SOP-14 package format. This series is designed to reduce board space and simplify layout by integrating the oscillator circuit. It serves as a standalone timer solution for systems where internal MCU RTC accuracy or power efficiency is insufficient.

Real Time Clock Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the source documentation. When evaluating alternatives, ensure compatibility with the 3-wire serial interface, SOP-14 footprint, and the 1.4 V to 5.5 V operating voltage range.