The DS1904 RTC iButton® is a rugged real-time clock module that can be accessed with minimal hardware. Data is transferred serially by 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.
关键特性
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
Unique, factory-lasered and tested 64-bit registration number (8-bit family code + 48-bit serial number + 8-bit CRC tester) assures absolute traceability because no two parts are alike
Multidrop controller for MicroLAN
Digital identification and information by momentary contact
Chip-based data carrier compactly stores information
Data can be accessed while affixed to object
Economically communicates to host with a single digital signal at 16.3kbits per second
Standard 16mm diameter and 1-Wire protocol ensure compatibility with iButton device family
Button shape is self-aligning with cup-shaped probes
Durable stainless steel case engraved with registration number withstands harsh environments
Easily affixed with self-stick adhesive backing, latched by its flange, or locked with a ring pressed onto its rim
Presence detector acknowledges when reader first applies voltage
Meets UL#913 (4th Edit.); Intrinsically Safe Apparatus, approved under Entity Concept for use in Class I, Division 1, Group A, B, C and D locations (application pending)
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
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