1337ACSRI

Overview

The ISL12057 is a low-power, I2C real-time clock/calendar with alarm functions, functionally equivalent to the Maxim DS1337. It 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. The device features two alarms settable to the second, minute, hour, day of the week, or date, and provides four selectable frequency outputs. It operates with an external 32.768kHz crystal and supports a 400kHz data transfer rate. Key parameters include a time-keeping current of 0.5µA, a supply voltage range starting at 1.4V, and package options including 8-lead UTDFN, MSOP, and SOIC.

Feature Summary

• Pin compatible and functionally equivalent to Maxim DS1337
• Dual interrupts for frequency output and alarm functions
• Four selectable frequency outputs
• Calendar accurate through 2099 with automatic leap year correction

Applications

• Utility Meters
• HVAC Equipment
• Audio/Video Components
• Set-Top Box/Television
• Network Routers, Hubs, Switches, Bridges

Procurement Notes

Verify the specific suffix (e.g., C, S, RI) against the manufacturer's datasheet to confirm temperature range, package type, and RoHS compliance status. Ensure the ordering code matches the required lead count and pitch dimensions for the selected package variant such as MSOP, SOIC, or UTDFN.

Selection Notes

Select this component when a pin-compatible replacement for the Maxim DS1337 is required. Consider the 0.5µA time-keeping current for battery-backed applications. Verify that the 1.4V minimum supply voltage aligns with the system power rails. Confirm the need for dual IRQ pins and four frequency outputs before finalizing the design.

Part Context

The ISL12057 belongs to Renesas' portfolio of low-cost, low-power real-time clocks. It serves as a direct functional alternative to legacy Maxim Integrated RTCs, maintaining compatibility while offering modern packaging options like the small 2mmx2mm UTDFN. This part is designed for applications requiring precise timekeeping with minimal power consumption.

Replacement Considerations

The ISL12057 is explicitly stated to be functionally equivalent and pin-compatible with the Maxim DS1337. Designers replacing older designs should verify that the DS1337 source document confirms this equivalence for their specific revision.