PT7C43390LEX

Real Time Clock Overview

The PT7C43390 is a Real-time Clock (RTC) module manufactured by Diodes Incorporated. It features an I2C bus interface and supports both 12-hour and 24-hour time formats. The device includes alarm interrupt pins, a programmable square wave output, and clock calibration capabilities. Operating voltage ranges from 1.35V to 5.5V, with a timekeeping range of 1.25V to 5.5V. Current consumption is typically 0.3µA out of communication at 3.0V. It supports burst mode communication and includes power-on and low-voltage detection circuits.

Real Time Clock Feature Summary

• I2C Bus Interface: Supports standard (100kHz) and fast mode (400kHz) with burst mode capability.
• Dual Interrupt Pins: INT1 and INT2 support alarm interrupts, user-set frequency outputs, and per-minute edge/periodical interrupts.
• Clock Calibration: Includes a dedicated register for frequency adjustment to maintain accuracy.
• Low Power Operation: Typical current consumption of 0.3µA at 3.0V when not communicating; timekeeping down to 1.25V.

Real Time Clock Applications

• Battery-backed real-time clock systems
• Data logging devices requiring precise timestamping
• Embedded systems with I2C connectivity
• Alarm-based monitoring equipment

Real Time Clock Procurement Notes

Verify the specific package variant (SOIC-8L, TSSOP-8L, or TDFN2x3-8L) required for the design, as the base part number PT7C43390 covers multiple packages. Confirm RoHS compliance status for the specific ordering suffix. Check lead times and availability directly with authorized distributors, as stock levels fluctuate.

Real Time Clock Selection Notes

Select based on required package type and operating temperature range (-40°C to +85°C). Ensure the external crystal load capacitance matches the recommended values (6pF or 12.5pF) for optimal oscillation start characteristics. Verify that the I2C pull-up resistors are compatible with the open-drain outputs of SDA, INT1, and INT2.

Real Time Clock Part Context

The PT7C43390 is part of Diodes Incorporated's RTC portfolio, designed for low-power applications. It integrates oscillator, divider, timing generator, and alarm comparators into a single chip. The device is compliant with EU RoHS directives and offers free register access for flexible system integration.

Real Time Clock Replacement Considerations

No direct public substitute part numbers are listed in the provided documentation. When selecting alternatives, ensure compatibility with I2C protocol, voltage range (1.35V-5.5V), and pinout configuration if physical replacement is required.

Real Time Clock FAQ

What is the maximum I2C clock frequency supported?

The PT7C43390 supports a maximum SCL clock frequency of 400 kHz in fast mode.

How does the device handle low power supply voltage?

It includes a low power supply voltage detection circuit. A BLD flag in Status Register 1 is set to '1' when VDD drops below the detection voltage (typically 1.05V), indicating potential data loss.

Can the PT7C43390 operate in both 12-hour and 24-hour modes?

Yes, the device supports both 12-hour and 24-hour time formats, selectable via the 12/24 bit in Status Register 1.

What is the purpose of the Clock Correction Register?

The Clock Correction Register allows users to adjust the oscillator frequency to compensate for crystal inaccuracies or environmental drift, ensuring long-term timekeeping precision.