DS1284

Overview

The DS1284 is a Real-Time Clock (RTC) integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides clock and calendar functions with a parallel interface, housed in a 28-DIP package. The device supports date formats of YY-MM-DD-dd and time formats of HH:MM:SS:hh in both 12-hour and 24-hour modes. It includes 50 bytes of static RAM for data storage. Operating parameters include a supply voltage range of 4.5V to 5.5V and a battery backup voltage range of 2.4V to 3.5V. The maximum current consumption during timekeeping is 7mA at 5V, with an operating temperature range of 0°C to +70°C.

Feature Summary

• Integrated Alarm, Leap Year correction, Square Wave Output, SRAM, and Watchdog Timer functionalities
• Parallel bus interface for direct connection to microprocessors
• 50-byte non-volatile static RAM for user data storage
• Dual voltage support: 4.5V–5.5V main supply and 2.4V–3.5V battery backup

Applications

• Industrial control systems requiring precise timekeeping
• Data logging equipment needing timestamp capabilities
• Embedded systems utilizing watchdog timer features for reliability

Procurement Notes

Verify the specific package variant required, as the DS1284 series includes DIP and PLCC options. Confirm RoHS compliance status, as some listings indicate non-compliance. Check availability status, as this component may be discontinued or subject to limited supply constraints depending on the manufacturer's production lifecycle.

Selection Notes

Select the DS1284 when a parallel interface is preferred over serial alternatives like I2C. Ensure the system design accommodates the 28-pin DIP footprint and the 4.5V–5.5V power supply requirements. Consider the 50-byte SRAM capacity against application memory needs. Verify that the 0°C to +70°C operating temperature range meets environmental specifications.

Part Context

The DS1284 belongs to the Maxim Integrated RTC family, designed for standalone real-time clock applications. It is part of a broader lineup that includes variants with different interfaces and packages, such as the DS12887+ and DS1286. This specific model focuses on parallel connectivity and basic RTC functions without additional complex peripherals found in higher-end models.

Replacement Considerations

Direct replacements within the same family include the DS1286, which offers similar functionality but may differ in package or pinout. For serial interface upgrades, consider the DS1307+, though architectural changes are required. Verify pin compatibility and software register mapping before substituting.