RV5C387A-E2-F

Real Time Clock Overview

The RV5C387A-E2-F is a CMOS real-time clock IC featuring an I2C bus serial interface and a supply voltage monitoring function. It maintains time and calendar data in BCD format, supporting automatic leap year identification up to 2099. The device operates with a timekeeping supply voltage ranging from 1.45 V to 5.5 V and consumes a typical supply current of 0.35 µA at 3 V. It includes two alarm circuits, a periodic interrupt circuit with selectable frequencies, and a 32-kHz clock output. High-precision oscillation adjustment corrects frequency deviations within ±189 ppm. The component is housed in an ultra-compact 10-pin SSOP-G package.

Real Time Clock Feature Summary

• I2C bus compatible interface (400 kHz) for CPU connection
• Low power consumption: Typical 0.35 µA at 3 V
• Built-in oscillation stabilization capacitors and high-precision adjustment circuit
• Supply voltage monitoring with selectable thresholds (1.6 V or 2.1 V)

Real Time Clock Applications

• Communication devices such as multi-function phones and portable phones
• OA devices including fax machines and portable faxes
• Computer peripherals like PDAs and portable word-processors
• AV components such as digital cameras and remote controllers

Real Time Clock Procurement Notes

Verify the specific suffix -E2-F against the manufacturer's official documentation to confirm packaging details and compliance status. Ensure that the I2C pull-up voltages align with the host CPU requirements, as the SCL and SDA pins tolerate up to 5.5 V regardless of the supply voltage.

Real Time Clock Selection Notes

Select this model when low standby current and precise timekeeping are required without external calibration components due to built-in capacitors. The dual alarm circuits and periodic interrupts support complex scheduling tasks. Ensure the application environment stays within the -40°C to +85°C operating temperature range for specified electrical characteristics.

Real Time Clock Part Context

The RV5C387A belongs to Nisshinbo Micro Devices' lineup of CMOS real-time clock ICs designed for battery-backed systems. It integrates timekeeping, calendar counting, and system monitoring functions into a single compact package, reducing board space and component count compared to discrete solutions.

Real Time Clock Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided source material. Verify pin compatibility and register mapping if considering alternative RTC ICs from other manufacturers.

Real Time Clock FAQ

How does the RV5C387A handle oscillation frequency deviations?

It features a high-precision oscillation adjustment circuit that allows correction of time count gain or loss within a maximum range of approximately ±189 ppm in increments of about 3 ppm.

What is the function of the XSTP bit?

The XSTP bit senses oscillation halts caused by events like power-on from 0 volts or supply voltage drops. It holds a '1' state to indicate invalid data until cleared by writing '0'.

Can the 32-kHz clock output be disabled?

Yes, the 32-kHz clock output can be disabled by setting both the CLEN1 bit in Control Register 2 and the CLEN2 bit in Control Register 1 to '1'.