ISL12027IBZ-T

Real Time Clock Overview

The ISL12027IBZ-T is a low-power Real Time Clock (RTC) and calendar integrated circuit manufactured by Renesas Electronics. It features an I2C interface, 512x8-bit EEPROM, and intelligent battery backup switching. The device operates with a main supply voltage of 2.7V to 5.5V and a backup supply of 1.8V to 5.5V. Key specifications include a battery supply current of 800nA at 1.8V, a watchdog timer, and two non-volatile alarms. It utilizes an external 32.768kHz crystal and includes on-chip oscillator compensation. 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

• I2C Bus Interface: Supports data transfer rates up to 400kHz for efficient communication.
• On-Chip Oscillator Compensation: Includes internal feedback resistors and a 64-position digitally controlled trim capacitor for frequency adjustment within ±30ppm.
• Integrated Memory: Contains 512x8-bit EEPROM with 16-byte page write mode and BlockLock protection.
• CPU Supervisor Functions: Features Power-On Reset, Low Voltage Reset, and a Watchdog Timer with selectable periods.

Real Time Clock Applications

• Utility Meters
• HVAC Equipment
• Network Routers, Hubs, Switches, Bridges
• POS Equipment
• Home Appliances

Real Time Clock Procurement Notes

The ISL12027IBZ-T is designated as an obsolete product with no recommended replacement available from the manufacturer. Verification of availability should be conducted through authorized distributors or secondary market suppliers, as standard production channels do not support this part number. Technical support inquiries regarding legacy status should be directed to the manufacturer's support center.

Real Time Clock Selection Notes

Select the ISL12027IBZ-T for applications requiring precise timekeeping with integrated non-volatile storage and supervisor functions. Ensure the design accommodates an external 32.768kHz quartz crystal connected to X1 and X2 pins. Verify that the system voltage requirements align with the 2.7V to 5.5V VDD range and that the I2C bus timing characteristics meet the controller's specifications.

Real Time Clock Part Context

This component belongs to the ISL12027 family of real-time clocks. The 'IB' suffix indicates an 8-lead SOIC package, while the '-T' suffix denotes tape and reel packaging. It is distinct from the ISL12027A variant, which utilizes different power control settings and is intended for applications where VBAT exceeds VDD.

Real Time Clock Replacement Considerations

The datasheet explicitly states there is no recommended replacement for this obsolete product. Engineers must evaluate alternative RTCs with similar I2C interfaces, EEPROM capacity, and package dimensions, ensuring compatibility with existing firmware and hardware constraints.

Real Time Clock FAQ

["What is the battery supply current consumption?","The battery supply current (IBAT) is typically 800nA at VBAT = 1.8V and 850nA at VBAT = 3.0V, with VDD and other pins grounded."]

["How does the device handle oscillator accuracy?","The ISL12027 integrates on-chip oscillator compensation with a 64-position digitally controlled trim capacitor and 6 digital frequency adjustment settings to correct frequency deviations up to ±30ppm."]

["What are the watchdog timer periods?","The watchdog timer offers three selectable time-out periods: 0.25 seconds, 0.75 seconds, and 1.75 seconds, based on the 32.768kHz crystal frequency."]