DS17285E-3+

Real Time Clock Overview

The DS17285E-3+ is a real-time clock (RTC) integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides timekeeping, calendar functions, and 2048 bytes of battery-backed nonvolatile SRAM. The device features a multiplexed byte-wide interface and supports both +3.0V and +5.0V operation. Key specifications include a supply voltage range of 2.7V to 3.7V for VCC in the -3 variant, with an operating temperature range of 0°C to +70°C. It includes automatic leap year compensation through 2099, power-fail detection, and system power-on control via alarm or external stimulus.

Real Time Clock Feature Summary

• Incorporates 2048 bytes of extended battery-backed NV SRAM alongside standard RTC registers.
• Features power-control circuitry allowing system power-on from date/time alarms or key closures.
• Includes a 64-bit silicon serial number and SMI recovery stack.
• Supports optional crystal load capacitance selection (6pF or 12.5pF) and operates in 12-hour or 24-hour formats.

Real Time Clock Applications

• Embedded systems requiring precise timekeeping.
• Utility meters for data logging and timestamping.
• Security systems needing backup power and alarm capabilities.
• Network hubs, bridges, and routers for synchronization.

Real Time Clock Procurement Notes

Verify the specific suffix 'E' against official documentation to confirm package type and temperature grade, as datasheets list PDIP, SO, and TSOP options. Confirm RoHS compliance status and lead-free designation associated with the '+' suffix. Ensure primary and auxiliary battery inputs are correctly configured for the selected voltage mode.

Real Time Clock Selection Notes

Select the DS17285E-3+ when 2KB of extended NV SRAM is required alongside standard RTC functionality. Choose the -3 suffix for +3.0V compatible systems and -5 for +5.0V systems. Consider the EDIP package variants if an integrated quartz crystal and lithium energy source are preferred over discrete components.

Real Time Clock Part Context

The DS17285 series serves as a successor to the industry-standard DS12885 and DS12887 devices. It enhances legacy functionality with additional memory, silicon serial numbers, and advanced power management features while maintaining compatibility with existing multiplexed bus interfaces used in PC clock designs.

Real Time Clock Replacement Considerations

The DS12885SN+ is a direct predecessor with similar functionality but lacks the extended 2KB SRAM and enhanced power control features found in the DS17285 series. Verify pinout compatibility and software register mapping differences when migrating from older DS1288x parts.