ISL12027IB27Z

Real Time Clock Overview

The ISL12027IB27Z is a low-power Real Time Clock (RTC) and calendar integrated circuit manufactured by Renesas Electronics. It features an I2C interface with a maximum data transfer rate of 400kHz, operating within a supply voltage range of 2.7V to 5.5V. The device includes two non-volatile alarms, automatic battery backup switching, and on-chip oscillator compensation with a 64-position digitally controlled trim capacitor. It integrates 512x8-bit EEPROM with BlockLock protection and provides CPU supervisory functions including a watchdog timer and power-fail indicator. The component is housed in an 8-lead SOIC package and supports an operating temperature range of -40°C to +85°C.

Real Time Clock Feature Summary

• Integrated 512x8-bit EEPROM with 16-byte page write mode and 8 modes of BlockLock protection
• On-chip oscillator compensation using internal feedback resistors and capacitors for ±30ppm accuracy
• Two non-volatile alarms settable to second, minute, hour, day of week, day, or month with repeat mode
• Automatic backup switching between VDD and VBAT with intelligent battery management

Real Time Clock Applications

• Utility meters
• HVAC equipment
• Audio/Video components
• Network routers, hubs, switches, and bridges
• Cellular infrastructure equipment

Real Time Clock Procurement Notes

The ISL12027IB27Z is classified as an obsolete product with no recommended replacement available from the manufacturer. Verification of current availability requires direct contact with technical support centers, as standard distribution channels may not stock this discontinued item. Designers should assess end-of-life status before finalizing procurement plans.

Real Time Clock Selection Notes

Select the ISL12027IB27Z when legacy mode power control settings are required, specifically where VBAT exceeds VDD. This variant differs from the ISL12027A, which utilizes standard mode settings. Ensure the application environment stays within the specified -40°C to +85°C temperature range and that the I2C bus timing constraints are met for reliable communication.

Real Time Clock Part Context

This component belongs to the ISL12027 family of real-time clocks, which also includes variants like the ISL12027A and different package options such as TSSOP. The IB27Z suffix denotes the 8-lead SOIC package with a specific VRESET voltage level of 2.63V and BSW bit default setting of 1. It shares functional similarities with other RTCs but is distinct in its power control configuration and EEPROM integration.

Real Time Clock Replacement Considerations

No recommended replacement part numbers are provided by the manufacturer for this obsolete device. Engineers must evaluate alternative RTC solutions independently, considering pin compatibility, interface protocols, and feature sets to ensure seamless integration into existing designs.