ISL1208IB8-TK

Real Time Clock Overview

The ISL1208IB8-TK is a low-power real-time clock (RTC) and calendar integrated circuit manufactured by Renesas Electronics Corporation. It operates within a supply voltage range of 2.7V to 5.5V and features an I2C interface with a maximum data transfer rate of 400kHz. The device tracks time in hours, minutes, and seconds, and includes calendar registers for date, month, year, and day of the week, accurate through 2099 with automatic leap year correction. It consumes 4µA to 6µA at 3V to 5V during operation. Key specifications include a battery backup current of 400nA, an operating temperature range of -40°C to +85°C, and an 8-lead SOIC package.

Real Time Clock Feature Summary

• Integrated oscillator compensation with a digital capacitor adjustment range of -94 ppm to +140 ppm to correct crystal frequency drift.
• Automatic backup switching between main power and a backup source (battery or supercapacitor) without additional external components.
• Includes 2 bytes of battery-backed user SRAM for non-volatile data storage.
• Configurable single alarm settable to second, minute, hour, day of week, day, or month, supporting event or pulse interrupt modes.

Real Time Clock Applications

• Three-phase PFC inverters requiring precise timing control.
• LoRaWAN street light controllers for AC loads.
• High-efficiency electromagnetic heaters.
• Advanced E/E architecture automotive computers.

Real Time Clock Procurement Notes

Verify the specific suffix 'TK' against the manufacturer's official datasheet to confirm packaging details, as standard listings may vary between tape-and-reel and cut-tape formats. Confirm RoHS compliance status and moisture sensitivity level (MSL 1) prior to procurement. Ensure the ordering part number matches the exact pinout and electrical characteristics required for the target design.

Real Time Clock Selection Notes

Select this component when a low-power RTC with integrated frequency compensation and battery-backed SRAM is required. It is suitable for designs needing automatic power-fail detection and intelligent battery backup switching. The I2C interface and small 8-SOIC package make it compatible with space-constrained microprocessor systems. Verify that the external 32.768 kHz crystal meets the load capacitance requirements specified in the datasheet.

Real Time Clock Part Context

The ISL1208 belongs to the ISL1208 family of real-time clocks from Renesas (formerly Intersil). It shares pin compatibility with ST M41Txx and Maxim DS13xx devices, facilitating drop-in replacements in existing designs. The 'IB8Z' designation typically indicates the SOIC-8 package variant, while '-TK' denotes the specific shipping configuration.

Real Time Clock Replacement Considerations

Direct pin-compatible substitutes include ST M41Txx series and Maxim DS13xx series RTCs. For applications requiring similar functionality but different packages, consider the ISL1208IB8Z (SOIC-8) or ISL1208IM8Z (MSOP-8). Verify that any replacement maintains the same I2C address and register map if software migration is not planned.