DS12885QN/T&R

Overview

The DS12885QN/T&R is a real-time clock and calendar IC manufactured by Analog Devices Inc./Maxim Integrated. It provides timekeeping in HH:MM:SS (12/24 hour) format and date tracking in YY-MM-DD-dd format, including automatic leap year correction. The device integrates 114 bytes of battery-backed static RAM (NVSRAM). It operates with a main supply voltage of 4.5V to 5.5V and a backup battery range of 2.5V to 4V. Maximum current consumption during timekeeping is 15mA at the primary supply voltage. The component utilizes a parallel interface and is housed in a 28-PLCC package.

Feature Summary

• Integrated 114-byte NVSRAM for data retention
• Automatic leap year adjustment and daylight savings support
• Programmable square wave output and one time-of-day alarm
• Three maskable interrupts with common interrupt output

Applications

• Industrial systems requiring precise timekeeping
• Data logging equipment with non-volatile storage needs
• Embedded controllers utilizing parallel interfaces

Procurement Notes

Verify the specific suffix 'T&R' indicates Tape & Reel packaging when sourcing. Confirm the operating temperature grade corresponds to the industrial range (-40°C to 85°C) required for the application environment. Ensure compatibility with the 28-LCC J-Lead footprint on the target PCB design.

Selection Notes

Select this component if a parallel interface is preferred over serial alternatives like I2C or SPI. The 114-byte memory capacity suits applications requiring moderate local data storage alongside timekeeping. Verify that the system power architecture supports the specified 4.5V to 5.5V logic levels and 2.5V to 4V battery backup requirements.

Part Context

The DS12885 series serves as a direct replacement for legacy DS1285 and DS1287 devices. It belongs to the Maxim Integrated RTC family, which also includes variants like the DS12887 and DS1689. The 'QN' designation typically refers to the plastic PLCC package variant within this product line.

Replacement Considerations

The datasheet identifies the DS1285 and DS1287 as direct functional replacements. Other members of the same family, such as the DS12887Q or DS1689SN, may offer similar functionality but differ in pin count, memory size, or package type.