DS1284Q

Overview

The DS1284Q is a Real-Time Clock (RTC) integrated circuit manufactured by Analog Devices Inc./Maxim Integrated. It provides clock and calendar functions with a 50-byte SRAM storage capacity. The device utilizes a parallel interface and 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 operates within a supply voltage range of 4.5V to 5.5V, drawing a maximum current of 7mA at 5V during timekeeping. The component is housed in a 28-PLCC package with J-leads and is designed for surface mount installation.

Feature Summary

• Integrated clock/calendar functionality with 50B SRAM
• Parallel bus interface supporting standard addressing
• Built-in alarm, leap year compensation, and watchdog timer
• Square wave output capability for system synchronization

Applications

• Industrial control systems requiring precise timekeeping
• Data logging equipment needing calendar tracking
• Embedded systems with parallel microprocessor interfaces

Procurement Notes

Verify the specific manufacturer lot and RoHS compliance status before procurement, as legacy components may have varying environmental certifications. Confirm that the 28-PLCC footprint matches the target PCB design, noting the J-lead package dimensions are 11.51x11.51 mm. Ensure the power supply architecture supports the 4.5V to 5.5V operating range and battery backup requirements of 2.4V to 3.5V.

Selection Notes

Select this component when a parallel interface is required for RTC integration with legacy or specific microcontroller architectures. The 50-byte SRAM is suitable for applications not requiring large non-volatile data storage. Verify that the 0°C to 70°C commercial temperature range meets the operational environment constraints. Consider the square wave output if periodic interrupt generation is needed without additional logic.

Part Context

The DS1284Q belongs to the Maxim Integrated DS1284/DS1286 family of real-time clocks. These devices are designed to provide time-of-day and calendar information to microprocessors via a parallel interface. The 'Q' suffix typically denotes the plastic PLCC package variant within this product line, distinguishing it from ceramic DIP options.

Replacement Considerations

Direct pin-to-pin replacements within the same family include the DS1284QN (same function, different package variant) or the DS1286 series which offers expanded memory. Verify interface compatibility when substituting with other parallel RTCs, as register maps may differ.