R2045S-E2-FE

Real Time Clock Overview

The R2045S-E2-FE is a CMOS real-time clock module featuring a built-in 32.768 kHz crystal oscillator and a four-wire serial interface (CE, SCLK, SI, SO). It operates within a timekeeping voltage range of 1.15 V to 5.5 V with typical current consumption of 0.48 µA at 3 V. The device provides BCD-format time and calendar counters, two alarm interrupt circuits, and selectable periodic interrupts ranging from 0.5 seconds to one month. It includes an oscillation adjustment circuit for frequency correction, supply voltage monitoring, and a 32 kHz clock output pin.

Real Time Clock Feature Summary

• Four-wire serial interface with maximum clock frequency of 1 MHz
• Built-in high-precision crystal oscillator adjusted to ±5 ppm at 25°C
• Super low power consumption: 0.48 µA typical at VDD=3V
• Automatic leap year identification up to the year 2099

Real Time Clock Applications

• Embedded systems requiring precise timekeeping
• Battery-powered devices with low power constraints
• Industrial equipment needing supply voltage monitoring
• Consumer electronics with calendar functions

Real Time Clock Procurement Notes

Verify the package type corresponds to SOP14, as indicated by the 'S' designation in the part number. Confirm the lead plating specification matches 'FE' for lead-free plating. Ensure the ordering suffix 'E2' aligns with the required taping type. Cross-reference the datasheet revision NO.EA-113-230419 for accurate electrical characteristics.

Real Time Clock Selection Notes

Select this component when a four-wire serial interface is preferred over I2C or SPI. Consider the R2045S-D series if SON22 packaging is required, noting that the R2045D variant was discontinued in April 2023. Evaluate the need for the 32 kHz clock output function and the specific supply voltage monitoring thresholds (1.3 V or 2.1 V) before finalizing the design.

Real Time Clock Part Context

The R2045S-E2-FE belongs to the R2045S/D series manufactured by Nisshinbo Micro Devices Inc. The 'S' indicates the SOP14 package, while 'FE' denotes lead-free plating. This series integrates a CMOS RTC IC with a crystal unit, designed for high precision and low power applications. The R2045D (SON22) version is discontinued.

Real Time Clock Replacement Considerations

The R2045D (SON22) package variant is discontinued as of April 2023. No direct equivalent part numbers are listed in the provided documentation. Designers should verify compatibility with existing board layouts if substituting with other RTC modules, as the four-wire serial interface differs from standard I2C protocols.