ISL12027IB27Z-T

Real Time Clock Overview

The ISL12027IB27Z-T is a low-power real-time clock/calendar integrated circuit manufactured by Renesas Electronics Corporation. 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 of 2.7V to 5.5V and supports battery backup down to 1.8V. Key specifications include a maximum battery supply current of 1µA at 1.8V, a VBAT trip threshold of 2.63V, and a default backup switching bit setting of 1. It utilizes an external 32.768kHz crystal and provides oscillator compensation for accuracy.

Real Time Clock Feature Summary

• I²C Interface: Supports data transfer rates up to 400kHz with open-drain SDA and active SCL inputs.
• On-Chip Oscillator Compensation: Includes internal feedback resistors, compensation capacitors, and a 64-position digitally controlled trim capacitor for frequency adjustment within ±30ppm.
• EEPROM Memory: Provides 512x8 bits (4k bits) of non-volatile storage with 16-byte page write mode and eight modes of BlockLock protection.
• Supervisory Functions: Integrates a watchdog timer with selectable periods (0.25s, 0.75s, 1.75s), power-on reset, and low-voltage sensing.

Real Time Clock Applications

• Utility Meters
• HVAC Equipment
• Network Routers, Hubs, Switches, Bridges
• Cellular Infrastructure Equipment
• POS Equipment

Real Time Clock Procurement Notes

Verify the -T suffix indicates tape and reel packaging as specified in the datasheet ordering information. Confirm the IB27Z variant corresponds to the 8-lead SOIC package with a 2.63V VBAT trip point and BSW=1 default setting. Check for obsolete status or recommended replacement notices from the manufacturer.

Real Time Clock Selection Notes

Select this component for applications requiring precise timekeeping with automatic leap year correction through 2099. Ensure the design accommodates the 2.63V VBAT trip threshold and the specific Legacy Mode power control settings associated with the ISL12027 series. Verify compatibility with the required I²C bus voltage levels and pull-up resistor configurations.

Real Time Clock Part Context

This part belongs to the ISL12027 family of real-time clocks. The 'IB' designation indicates an 8-lead SOIC package, while '27Z' specifies the 2.63V VBAT trip point and Pb-free construction. The '-T' suffix denotes tape and reel packaging. The device is distinct from the ISL12027A, which uses Standard Mode power control settings.

Real Time Clock Replacement Considerations

The datasheet marks the product as obsolete with no recommended replacement. Contact the Technical Support Center for potential alternatives.

Real Time Clock FAQ

["What is the default setting for the Backup Switching (BSW) bit?","The default setting for the BSW bit is 1."]

["How does the device handle oscillator frequency accuracy?","The device includes on-chip oscillator compensation with a 64-position digitally controlled trim capacitor and six digital frequency adjustment settings to achieve accuracy within ±30ppm."]

["What is the function of the RESET pin?","The RESET pin is an open-drain active LOW output that notifies the host processor when the watchdog timer expires or when the VDD voltage drops below the VTRIP threshold."]