ISL12028IVAZ-T

Real Time Clock Overview

The ISL12028IVAZ-T is a low-power real-time clock/calendar integrated circuit manufactured by Renesas Electronics. It features an I2C bus interface with a maximum data transfer rate of 400kHz and operates within a supply voltage range of 2.7V to 5.5V on VDD, while the backup supply (VBAT) supports 1.8V to 5.5V. The device includes 512x8-bit EEPROM, automatic leap year correction through 2099, and intelligent battery backup switching. Key electrical parameters include a typical battery supply current of 800nA at 1.8V and a main timekeeping current of 10µA at 2.7V. It is housed in a 14-lead TSSOP package.

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 capability and hardware interrupt output.
• On-chip oscillator compensation with 64-position digital trim 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, and bridges

Real Time Clock Procurement Notes

Verify component status as the datasheet identifies this part as obsolete with no recommended replacement. Confirm availability through authorized distributors or surplus channels, as standard manufacturing may have ceased. Ensure the specific suffix matches the required package and temperature range specifications before procurement.

Real Time Clock Selection Notes

Select the ISL12028 variant based on the required VBAT trip point and power control mode. The 'IV' suffix indicates a 14-lead TSSOP package suitable for surface mount applications. Verify that the system design accommodates the specific VRESET threshold and battery backup switching requirements defined in the ordering information table.

Real Time Clock Part Context

This component belongs to the ISL12028 family of real-time clocks produced by Intersil, now part of Renesas Electronics. The IVAZ-T designation specifies the 14-lead TSSOP package, industrial temperature range (-40°C to +85°C), and tape-and-reel packaging. It is distinct from the ISL12028A series which utilizes different power control settings.

Real Time Clock Replacement Considerations

The datasheet explicitly states this is an obsolete product with no recommended replacement. Engineers must evaluate alternative RTCs with compatible I2C interfaces and pinouts, ensuring new components meet the same voltage, temperature, and EEPROM capacity requirements.

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 battery backup switching?

The device features intelligent battery backup switching that automatically transitions power between VDD and VBAT upon power failure detection, maintaining clock and calendar operation with minimal current draw.

What is the data retention period for the internal EEPROM?

The integrated 512x8-bit EEPROM has a specified data retention period of 50 years when the ambient temperature is less than or equal to +75°C.