PT7C4339UEX

Real Time Clock Overview

The PT7C4339UEX is a low-power Real-Time Clock (RTC) module manufactured by Diodes Incorporated. It provides timekeeping and calendar functions including seconds, minutes, hours, day of the week, date, month, and year with leap-year compensation valid until 2100. The device utilizes an I2C serial interface supporting high-speed mode up to 400 kHz. It features two programmable time-of-day alarms, a programmable square-wave output, and automatic power-fail detection with switching to a backup supply. The unit operates within a temperature range of -40°C to +85°C and requires an external 32.768 kHz crystal oscillator.

Real Time Clock Feature Summary

• I2C Serial Interface: Supports high-speed mode (400 kHz) for efficient data transfer.
• Calendar & Timekeeping: BCD code counters for seconds, minutes, hours, day, date, month, and year with automatic leap-year adjustment.
• Dual Alarms: Two independent time-of-day alarms capable of triggering interrupt signals.
• Power Management: Automatic power-fail detect circuit switches operation to VBACKUP when VCC drops below the trip point.

Real Time Clock Applications

• Embedded systems requiring precise timekeeping in industrial environments.
• Consumer electronics needing calendar functionality with battery backup.
• Data logging devices requiring timestamp accuracy across power cycles.

Real Time Clock Procurement Notes

Verify that the specific suffix 'UEX' corresponds to the standard PT7C4339 package and tape-and-reel configuration as defined in the official datasheet. Confirm that the required external 32.768 kHz crystal is sourced separately, as this variant does not integrate the oscillator component unlike the PT7C4339C model.

Real Time Clock Selection Notes

Select the PT7C4339UEX over the PT7C4339C if an external crystal is preferred or already present on the PCB. Ensure the design accommodates the MSOP-8L or SOIC-8L package dimensions. Verify that the system voltage supports the recommended operating conditions of 3.0V to 5.5V for VCC and 1.3V to 3.7V for VBACKUP.

Real Time Clock Part Context

This component belongs to the PT7C4339 family of real-time clock modules from Diodes Incorporated. It is distinct from the PT7C4339C, which integrates a crystal oscillator within the TDFN4x4-8L package. The PT7C4339 series is designed for applications requiring robust timekeeping with minimal external components beyond the crystal.

Real Time Clock Replacement Considerations

The PT7C4339C serves as a functional alternative if integrated crystal usage is acceptable and the TDFN4x4-8L package fits the layout. Other RTCs with I2C interfaces may require significant register mapping and pinout adjustments.