ISL1208IB8ZR5291

Real Time Clock Overview

The ISL1208IB8ZR5291 is a low-power real-time clock (RTC) integrated circuit manufactured by Renesas Electronics Corporation. It features an I2C interface and operates within a supply voltage range of 2.7V to 5.5V, with battery backup support from 1.8V to 5.5V. The device tracks time in hours, minutes, and seconds and includes calendar registers accurate through 2099 with automatic leap year correction. It offers one selectable frequency output, a single alarm settable to the second, minute, hour, day of the week, day, or month, and 2 bytes of battery-backed user SRAM. The component is housed in an 8-SOIC package and supports data transfer rates up to 400kHz.

Real Time Clock Feature Summary

• Automatic backup switching between main power and battery/super capacitor sources upon power failure detection
• On-chip oscillator compensation for timing accuracy using an external 32.768kHz crystal
• Calendar functionality with automatic leap year correction valid through the year 2099

Real Time Clock Applications

• Industrial control systems requiring precise timekeeping
• Smart metering infrastructure
• IoT devices with low power consumption requirements

Real Time Clock Procurement Notes

Verify the specific suffix R5291 against official Renesas documentation to confirm if it denotes a unique tape-and-reel packaging variant or a specific manufacturing lot code distinct from standard tube packaging. Ensure compatibility with existing PCB footprints designed for standard 8-SOIC packages. Confirm RoHS compliance status via the latest datasheet revision before finalizing procurement specifications.

Real Time Clock Selection Notes

Select this component when a small form factor RTC with I2C connectivity and battery-backed SRAM is required. It serves as a pin-compatible alternative to ST M41Txx and Maxim DS13xx devices. Consider its low current consumption during battery operation and the availability of programmable alarms for event-driven system wake-ups.

Real Time Clock Part Context

The ISL1208 belongs to the ISL1208 series of real-time clocks from Renesas. This series is characterized by low power consumption, integrated oscillator compensation, and flexible alarm configurations. The IB8Z designation typically indicates the industrial temperature range and SOIC-8 package type, while the base model provides the core RTC and calendar functionalities documented in the official product specification.

Real Time Clock Replacement Considerations

The ISL1208 is noted to have the same pinout as ST M41Txx and Maxim DS13xx devices. Verify register-level compatibility and software driver adjustments when substituting these parts. No other direct public substitute part numbers are confirmed in the provided source material.