ISL12028IB27AZ-T

Real Time Clock Overview

The ISL12028IB27AZ-T is a low-power real-time clock/calendar integrated circuit manufactured by Renesas Electronics. It features an I2C bus interface, two non-volatile alarms, and 512x8-bit EEPROM with BlockLock protection. The device operates on a main supply voltage (VDD) of 2.7V to 5.5V and a backup supply (VBAT) of 1.8V to 5.5V. Key electrical parameters include a battery supply current of 800nA at 1.8V VBAT and a typical timekeeping current of 10µA at 2.7V VDD. It includes CPU supervisor functions such as Power-On Reset and a Watchdog Timer.

Real Time Clock Feature Summary

• Real-Time Clock/Calendar with automatic leap year correction through 2099
• Integrated 512x8-bit EEPROM with 16-byte page write mode and BlockLock protection
• Intelligent battery backup switching with power-fail detection
• On-chip oscillator compensation with 64-position digital trim capacitor

Real Time Clock Applications

• Utility Meters
• HVAC Equipment
• Network Routers, Hubs, Switches, Bridges
• POS Equipment
• Computer Products

Real Time Clock Procurement Notes

Verify the specific suffix 'AZ' against official Renesas documentation, as standard listings often show 'Z' or 'Z-T'. Confirm availability status, as many variants in this family are marked as obsolete or limited supply. Ensure the package type matches the required PCB footprint, typically SOIC-14 for this series.

Real Time Clock Selection Notes

Select the ISL12028 variant based on the required VRESET threshold; the IB27 designation indicates a 2.63V reset level. Choose between SOIC and TSSOP packages depending on board space constraints. Ensure the application requires the Legacy Mode setting associated with the ISL12028 rather than the Standard Mode of the ISL12028A.

Real Time Clock Part Context

This component belongs to the ISL12028 family of real-time clocks from Renesas (formerly Intersil). It is designed for applications requiring precise timekeeping with non-volatile memory storage. The device integrates oscillator compensation to minimize external component count, distinguishing it from basic RTCs that require external trim capacitors.

Real Time Clock Replacement Considerations

The datasheet explicitly states this product is obsolete with no recommended replacement. Contact Technical Support for potential alternatives. Cross-model compatibility exists within the ISL12028 family regarding pinout, but verify VRESET thresholds and power control settings (Legacy vs. Standard mode) before substitution.