Analog Devices Inc./Maxim Integrated DS24B33+T&R

Overview

DS24B33+T&R from Analog Devices is a 4096-bit, 1-Wire® EEPROM organized as 16 pages of 256 bits each, featuring a 32-byte scratchpad for write-verification, unique 64-bit factory-programmed registration number, and parasitic power operation via single IO pin. It operates from +2.8V to +5.25V across –40°C to +85°C and is used for calibration data storage, PCB identification, and product revision tracking in embedded sensor nodes and industrial control modules.

For engineers reviewing the DS24B33+T&R datasheet, DS24B33+T&R pinout, DS24B33+T&R application, or DS24B33+T&R equivalent, key selection considerations include 1-Wire bus timing compliance (standard/overdrive modes), scratchpad-based write integrity verification, EEPROM endurance at elevated temperature (+85°C = 50k cycles), parasitic power capability, and TO-92 tape-and-reel packaging for through-hole assembly.

Technical Context

The DS24B33+T&R implements a fully compliant 1-Wire slave interface with ROM function command support (Read/Match/Search/Skip ROM) followed by memory function commands (Write/Read Scratchpad, Copy Scratchpad, Read Memory). Its internal architecture includes a CRC-16 generator for command/data integrity, three address registers (TA1, TA2, E/S), and a 32-byte volatile scratchpad acting as write buffer before EEPROM commit.

Communication occurs at two speeds: standard mode (≤15.4kbps, tSLOT = 65µs) and overdrive mode (≤125kbps, tSLOT = 8µs), both requiring external pullup on the open-drain IO line. The device draws all operating power parasitically from the 1-Wire bus, with no VCC pin - energy is harvested during high bus states using internal charge pump circuitry.

Key Specifications

Pinout & Package

DS24B33+T&R is supplied in TO-92 package (2-pin, leaded through-hole) with leads formed to 100-mil (2.54 mm) spacing for tape-and-reel automated placement. Pin 1 is GND; Pin 2 is IO - no VCC or NC pins present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 1-Wire EEPROM applications.

Compared with DS2433+T&R, DS24B33+T&R offers higher thermal endurance and stronger ESD protection for harsh environments; compared with DS24B33S+T&R, it provides identical functionality in a lower-cost, through-hole-compatible TO-92 package optimized for manual or wave-solder assembly.

Availability

DS24B33+T&R is available at Aetrix Electronics and suitable for industrial sensor nodes, medical device calibration modules, and automotive subsystem identification requiring stable component supply, long-term data retention, and parasitic-power simplicity.

Supply support for DS24B33+T&R includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and connectivity applications.

The DS24B33+T&R belongs to Analog Devices' 1-Wire® EEPROM product line, designed specifically for low-pin-count, parasitically powered identification and configuration storage in distributed sensing and industrial control systems.

FAQ

Does DS24B33+T&R require an external power supply?

No, DS24B33+T&R operates exclusively via parasitic power drawn from the 1-Wire bus during high states - no VCC connection is needed. Its internal charge pump harvests energy from the IO line, making it ideal for space-constrained or battery-sensitive applications where minimizing external components is critical. The DS24B33+T&R design eliminates the need for dedicated power routing on the PCB.

What is the purpose of the scratchpad in DS24B33+T&R?

The 32-byte scratchpad in DS24B33+T&R serves as a volatile write buffer that enables data verification before committing to nonvolatile EEPROM. After writing data to the scratchpad, the host can read it back to confirm integrity - only then does the Copy Scratchpad command transfer verified data to permanent memory. This two-step process prevents corruption from bus noise or timing errors, a core reliability feature of the DS24B33+T&R architecture.

Is DS24B33+T&R pin-compatible with DS2433+T&R?

Yes, DS24B33+T&R is pin-compatible and software-compatible with DS2433+T&R in TO-92 packaging - both use identical 2-pin pinout (GND/IO) and share the same 1-Wire family code (0x23), command set, and memory map. Firmware and hardware designs for DS2433+T&R can integrate DS24B33+T&R without layout or code changes, delivering improved thermal endurance and ESD robustness.

What is the maximum communication speed supported by DS24B33+T&R?

DS24B33+T&R supports two 1-Wire speeds: standard mode up to 15.4kbps (tSLOT = 65µs) and overdrive mode up to 125kbps (tSLOT = 8µs). Overdrive mode requires explicit activation via Overdrive-Skip ROM or Overdrive-Match ROM commands and is enabled only after successful ROM function execution. Both modes operate across the full +2.8V to +5.25V IO voltage range specified for DS24B33+T&R.

How does DS24B33+T&R ensure unique device identification on a shared 1-Wire bus?

Each DS24B33+T&R contains a factory-programmed, unalterable 64-bit registration number comprising an 8-bit family code (0x23), 48-bit unique serial number, and 8-bit CRC. This number is used during ROM function commands (e.g., Match ROM, Search ROM) to select individual devices on multidrop buses - ensuring absolute part identity and error-free addressing without external configuration, a defining capability of the DS24B33+T&R.