ISL12028IV30AZ

Real Time Clock Overview

The ISL12028IV30AZ is a Real Time Clock/Calendar IC manufactured by Renesas Electronics Corporation, utilizing an I2C bus interface. It features integrated 512x8-bit EEPROM and operates within a voltage range of 2.7V to 5.5V for VDD and 1.8V to 5.5V for VBAT. The device provides timekeeping via separate registers for hours, minutes, and seconds, alongside calendar functions accurate through 2099 with automatic leap year correction. Key specifications include a battery supply current of approximately 800nA at 1.8V, a watchdog timer with selectable periods, and oscillator compensation capabilities.

Real Time Clock Feature Summary

• Integrated 512x8-bit EEPROM with BlockLock protection and >2,000,000 cycle endurance.
• Dual non-volatile alarms with periodic interrupt modes and hardware interrupt output.
• On-chip oscillator compensation with 64-position digital trim capacitor for frequency adjustment.
• CPU Supervisor functions including Power-On Reset, Low Voltage Sense, and Watchdog Timer.

Real Time Clock Applications

• Utility Meters
• HVAC Equipment
• Network Routers, Hubs, Switches, Bridges

Real Time Clock Procurement Notes

Verify component status as the datasheet identifies this series as obsolete with no recommended replacement. Confirm availability through authorized distributors or surplus channels, as standard manufacturing support may be discontinued. Ensure compatibility with existing design constraints given the end-of-life designation.

Real Time Clock Selection Notes

Select the ISL12028 variant based on the required VRESET threshold; the '30' suffix indicates a specific reset voltage level distinct from other family members. Ensure the application supports the TSSOP-14 package format. Verify that the system architecture accommodates the I2C interface timing requirements and pull-up resistor configurations specified in the electrical characteristics.

Real Time Clock Part Context

This component belongs to the ISL12028 family of real-time clocks produced by Renesas (formerly Intersil). The family includes variants such as ISL12028IB27Z and ISL12028IVZ, differing primarily in package type (SOIC vs. TSSOP) and internal configuration settings like backup switching modes and reset thresholds.

Real Time Clock Replacement Considerations

The datasheet explicitly states 'OBSOLETE PRODUCT NO RECOMMENDED REPLACEMENT'. Designers must evaluate alternative RTC solutions independently, considering pin compatibility, interface standards, and functional equivalence without official manufacturer substitution guidance.

Real Time Clock FAQ

What is the function of the IRQ/FOUT pin?

The IRQ/FOUT pin serves as a multi-functional output that can be configured as an interrupt signal for alarm events or as a frequency output providing 1Hz, 4096Hz, or 32,768Hz signals.

How does the device handle power failure detection?

The device monitors the VDD supply voltage against a fixed VTRIP threshold. If VDD drops below this threshold, the device automatically switches to the VBAT backup supply and asserts the RESET output if applicable.

What is the data retention period for the EEPROM?

The integrated 512x8-bit EEPROM offers a data retention period of 50 years when the temperature is maintained at or below +75°C.