iButton® Specialist and Manufacturer of Dallas Keys

DS1904 RTC iButton

DS1904L-F5# iButton®

Regular price

exc. VAT

Sale price
£4.22 exc. VAT
Regular price
exc. VAT
Sold out
Unit price
Shipping calculated at checkout.

DS1904 RTC iButton™

The DS1904L RTC iButton™ is a rugged real-time clock module that can be accessed with minimal hardware. Data is transferred serially via the 1-Wire™ protocol, which requires only a single data lead and a ground return. The DS1904 contains a unique 64-bit factory-lasered ROM and a real-time clock/calendar implemented as a binary counter. The durable MicroCan package is highly resistant to environmental hazards such as dirt, moisture, and shock. Accessories permit the DS1904 to be mounted on almost any surface including printed circuit boards and plastic key fobs. The DS1904 adds functions such as calendar, time and date stamp, stopwatch, hour meter, interval timer, and logbook to any type of electronic device or embedded application that uses a microcontroller.


Real-Time Clock/calendar in binary format
Uses the same binary time/date representation as the DS1994 but with 1 second resolution
Clock accuracy is better than ± 2 minutes per month at 25°C
Operating temperature range from -40°C to +70°C
Over 10 years of operation