ISL12028AIV27Z-T

Real Time Clock Overview

The ISL12028AIV27Z-T is a low-power Real Time Clock/Calendar with I2C bus interface and 512x8-bit EEPROM. It operates on a main supply of 2.7V to 5.5V and a backup supply of 1.8V to 5.5V, drawing 800nA in battery mode. The device features automatic leap year correction through 2099, two non-volatile alarms, and an integrated oscillator compensation network with ±30ppm accuracy. It includes CPU supervisor functions such as Power-On Reset, Low Voltage Sense, and a Watchdog Timer. The component is housed in a 14-lead TSSOP package.

Real Time Clock Feature Summary

• I2C Interface: Supports 400kHz data transfer rate with bidirectional serial data and clock lines.
• EEPROM Memory: 512x8 bits (4k bits) with 16-byte page write mode, >2,000,000 cycle endurance, and 50-year data retention.
• Oscillator Compensation: Internal feedback resistor and 64-position digitally controlled trim capacitor for frequency adjustment.
• CPU Supervisor: Includes Power-On Reset, Low Voltage Reset, and Watchdog Timer with selectable periods of 0.25s, 0.75s, or 1.75s.

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 specific suffix 'T' indicates tape and reel packaging per manufacturer tech brief TB347. Confirm the 'A' designation corresponds to Standard Mode power control settings, distinct from the Legacy Mode of the standard ISL12028. Check current availability status as the base part number may be subject to discontinuation notices.

Real Time Clock Selection Notes

Select this variant over the standard ISL12028 if the application requires VBAT > VDD operation, as the ISL12028A utilizes Standard Mode settings suitable for this condition. Ensure the 14-lead TSSOP package fits the PCB layout constraints. Verify that the 2.63V reset voltage level meets the system's low voltage detection requirements.

Real Time Clock Part Context

This component belongs to the ISL12028 family manufactured by Renesas Electronics (formerly Intersil). The 'ISL12028A' variant specifically addresses power control differences compared to the original ISL12028, utilizing Standard Mode settings. The 'IV27Z' suffix denotes the 14-lead TSSOP package with a 2.63V reset threshold and industrial temperature range.

Real Time Clock Replacement Considerations

The datasheet explicitly states this is an obsolete product with no recommended replacement. Contact Technical Support for potential alternatives.