DS1286

Overview

The DS1286 is a real-time clock/calendar integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides timekeeping and calendar functions with a parallel interface, supporting both 12-hour and 24-hour time formats alongside a YY-MM-DD-dd date format. The device includes 50 bytes of SRAM for data storage and features an integrated watchdog timer. It operates within a supply voltage range of 4.5V to 5.5V and supports battery backup voltages between 2.4V and 3.5V. Designed for through-hole mounting, it is housed in a 28-EDIP package with 23 leads.

Feature Summary

• Integrated watchdog timer for system reliability
• Automatic leap year correction up to 2100
• 50 bytes of battery-backed static RAM
• Programmable square wave output

Applications

• Industrial control systems requiring precise timekeeping
• Data logging equipment with timestamp requirements
• Embedded systems needing non-volatile time and date tracking

Procurement Notes

Verify the specific suffix code against the manufacturer's datasheet to confirm pinout compatibility and feature set variations. Ensure the selected package variant matches the required PCB footprint, as the standard unit utilizes a 28-EDIP housing. Confirm RoHS compliance status if environmental regulations apply to the target assembly process.

Selection Notes

Select this component when a parallel bus interface is preferred over serial alternatives like SPI or I2C. The 50-byte SRAM capacity suits applications with moderate data storage needs. Verify that the host microcontroller can support the parallel addressing scheme and timing requirements specified in the electrical characteristics section of the official documentation.

Part Context

The DS1286 belongs to the Maxim Integrated DS128x family of real-time clocks. This series is designed to replace older discrete RTC solutions by integrating timekeeping, calendar logic, and non-volatile memory into a single package. It shares architectural similarities with the DS1287 but offers distinct memory configurations and interface options tailored for specific embedded design constraints.

Replacement Considerations

The DS1287 is a direct functional replacement within the same product family. Both devices share identical pinouts and core timekeeping capabilities. Differences primarily involve the amount of available static RAM; verify that the 50-byte capacity of the DS1286 meets the application's data storage requirements compared to other variants.