DS1993

` 4096 bits of Read/Write Nonvolatile Memory (DS1993)
` 1024 bits of Read/Write Nonvolatile Memory (DS1992)
` 256-bit Scratchpad Ensures Integrity of Data Transfer
` Memory Partitioned into 256-bit Pages for Packetizing Data
` Data Integrity Assured with Strict Read/Write Protocols
` Operating Temperature Range from -40 to +70
` Over 10 years of data retention

Voltage on any Pin Relative to Ground .............................-0.5V to +7.0V
Operating Temperature Range .........................................-40 to +70
Storage Temperature Range ............................................-40 to +70

* This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.

The DS1992/DS1993 memory iButtons (hereafter referred to as DS199_) are rugged read/write data carriers that act as a localized database, easily accessible with minimal hardware. The nonvolatile memory and optional timekeeping capability offer a simple solution to storing and retrieving vital information pertaining to the object to which the iButton is attached. Data is transferred serially through the 1-Wire protocol that requires only a single data lead and a ground return.

The scratchpad DS1992/DS1993 is an additional page that acts as a buffer when writing to memory. Data is first written to the scratchpad where it can be read back. After the data has been verified, a copy scratchpad command transfers the data to memory. This process ensures data integrity when modifying the memory. A 48-bit serial number is factory lasered into each DS199_ to provide a guaranteed unique identity that allows for absolute traceability. The durable MicroCan package is highly resistant to environmental hazards such as dirt, moisture, and shock. Its compact coin-shaped profile is self-aligning with mating receptacles, allowing the DS199_ to be easily used by human operators. Accessories permit the DS199_ to be mounted on almost any surface including plastic key fobs, photoID badges, and PC boards.

Applications of DS1992/DS1993 include access control, work-in-progress tracking, electronic travelers, storage of calibration constants, and debit tokens.