ISL12028IV27AZ-T

Real Time Clock Overview

The ISL12028IV27AZ-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 digitally controlled trim capacitors for ±30ppm accuracy.
• 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 authenticity through authorized distributors or direct manufacturer channels. Confirm the specific suffix 'AZ' corresponds to the required VBAT trip point and BSW default settings as defined in the official datasheet. Ensure compliance with RoHS standards and check for any end-of-life notifications or obsolescence warnings prior to procurement.

Real Time Clock Selection Notes

Select this model when a 14-lead TSSOP package is required for space-constrained designs. The '27' suffix indicates a VRESET threshold of approximately 2.63V, suitable for systems where the main supply drops below higher reset thresholds. Ensure the application requires the Legacy Mode power control setting associated with the ISL12028 variant rather than the Standard Mode of the ISL12028A series.

Real Time Clock Part Context

This component belongs to the ISL12028 family of real-time clocks from Renesas/Intersil. It shares functional similarities with the ISL12028A but utilizes different power control settings. The IV27 designation specifically identifies the TSSOP package variant with a 2.63V reset threshold. The '-T' suffix typically denotes tape and reel packaging for automated assembly.

Real Time Clock Replacement Considerations

Public documentation lists this part as obsolete with no recommended replacement. Engineers must evaluate alternative RTCs with compatible I2C interfaces and pinouts. Verify that any substitute component meets the same voltage ranges, EEPROM capacity, and watchdog timer requirements.