What this 1-Wire EPROM is and where it fits
The Maxim Integrated DS2505+T&R is a 16 Kbit one-time-programmable EPROM that communicates over a single-wire bus — the 1-Wire interface. It stores 16 Kbit organized as 16K x 1, read with a 15 µs access time. The part is housed in a through-hole TO-92-3 package with formed leads, rated for -40°C to 85°C operation. Typical applications include accessory or cartridge identification, calibration constant storage, consumable tracking, and small configuration tables where the data is written once at the factory and never changed.
15 µs access time — what it means for the bus
The 15 µs access time is the time from the end of the read command to the data bit appearing on the 1-Wire line. For a 1-Wire master running at standard overdrive speed (roughly 15 µs per bit), this timing allows back-to-back reads without inserting wait states. If the host microcontroller's 1-Wire driver uses a tight bit-slot window, the 15 µs spec sets the upper bound on the read timing budget — the master must allow at least this long before sampling the line.
OTP memory — no field updates possible
Because the DS2505+T&R uses one-time-programmable EPROM cells, the data is written once and cannot be erased or rewritten. This is a deliberate choice for applications where tamper resistance or data integrity after factory programming is critical — consumable authentication, serialization, or calibration constants that must survive the product lifetime. For any BOM that might need field-updatable data, a 1-Wire EEPROM (such as the DS2431 or DS28E05) would be the correct alternative, though those parts are not pin-compatible with this TO-92-3 footprint.
Industrial temperature grade and package
The -40°C to 85°C operating range covers industrial, outdoor telecom, and automotive cabin environments. The TO-92-3 through-hole package is a standard three-lead transistor outline — easy to hand-assemble, socket, or wave-solder. The formed leads suit PCB mounting with 2.54 mm pitch. This is not a high-density package, but for a single identification or calibration memory on a sensor module or accessory board, the footprint is minimal.
Lifecycle and sourcing reality
The DS2505+T&R carries an Active lifecycle status per the manufacturer — no end-of-life notice, no last-time-buy window.