DS2484R+T - I2C-to-1-Wire Bridge, SOT-23-6 | Analog Devices
MPN: DS2484R+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.02 | $1.02 |
| 10 | $0.96 | $9.60 |
| 100 | $0.85 | $85.00 |
| 500 | $0.74 | $370.00 |
| 1,000 | $0.65 | $650.00 |
DS2484R+T Overview
What is an I2C-to-1-Wire bridge? An I2C-to-1-Wire bridge is a protocol-conversion integrated circuit that lets a host microcontroller (which natively speaks I2C) communicate with one or more 1-Wire slave devices such as iButtons, temperature sensors, battery ID monitors, and secure authenticators. The bridge sits between the I2C bus and the 1-Wire bus, generating precise reset, presence-detect, read-time-slot, and write-time-slot waveforms so the host only needs to issue high-level commands over I2C. In the power-management and analog-IC taxonomy, this is an interface bridge IC under the broader category of communication-bus bridges.
Key features of the DS2484R+T include user-adjustable 1-Wire timing for tRSTL, tMSP, tW0L, and tREC parameters via I2C configuration, internal strong pull-up (active pull-up) support to power high-current 1-Wire slaves during EEPROM writes or temperature conversions, and a low-power sleep mode. The device integrates a 1.8V ±5% and 3.3V ±5% operating point that matches modern low-voltage microcontrollers. The 6-pin SOT-23 footprint makes it one of the smallest I2C-to-1-Wire bridges available.
Technically, the DS2484 exposes a register-based command set over I2C that lets the host set the 1-Wire line low, read bit, write byte, perform reset, and read ROM ID without bit-banging. Internal timers offload the strict 1-Wire timing requirements from software, which is essential because 1-Wire timing is notoriously microcontroller-unfriendly. The integrated active pull-up automatically engages for the duration of a slave EEPROM write or temperature conversion.
Typical applications include battery-pack authentication with Maxim DS2431/DS28E15/DS28EC20 secure authenticators, multi-node temperature monitoring chains using DS18B20 or DS1922 sensors, iButton reader accessories, and any low-pin-count MCU design that needs 1-Wire access without dedicating a GPIO bit.
When designing with this part, observe the recommended 1-Wire pull-up resistor (typically 2.2kΩ for standard speed) and add a 100nF decoupling capacitor adjacent to VDD. Use the ADI evaluation kit (DS2484EVKIT) to accelerate firmware bring-up; the EV kit includes a mounted DS2484R+T, RJ11 connector, and downloadable PC software.
This page synthesizes distributor pricing, drop-in alternative candidates, and practical design notes not consolidated on a single vendor product page.
Drop-in alternatives for DS2484R+T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
DS2484R+U
✅ Drop-In📋 Reference alternative (not in catalog)
DS2484R+T
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$0.65 / Unit
View Datasheet →DS2484R+T Specifications
| Function | I2C-to-1-Wire Bridge |
| Bridge Direction | I2C master side / 1-Wire master side |
| Number of Channels | 1 |
| I2C Communication Speeds | Standard 100 kHz max, Fast 400 kHz max |
| 1-Wire Communication Speeds | Standard and Overdrive |
| Supply Voltage Range (VDD) | 1.71 V to 5.25 V |
| I2C Operating Voltages | 1.8 V ±5%, 3.3 V ±5% |
| 1-Wire Operating Voltages | 1.8 V ±5%, 3.3 V ±5% |
| Adjustable 1-Wire Timing | tRSTL, tMSP, tW0L, tREC (user-programmable) |
| Active (Strong) Pull-Up Support | Yes |
| Sleep Mode | Yes (low-power) |
| Operating Temperature | -40 C to +85 C |
| Package | SOT-23-6 (R) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
DS2484R+T Pin Configuration
| Pin 1 | VDD — Supply voltage (1.71 V to 5.25 V) |
| Pin 2 | GND — Ground reference |
| Pin 3 | IO — 1-Wire data line (open-drain, requires external pull-up) |
| Pin 4 | SDA — I2C serial data (open-drain, requires external pull-up) |
| Pin 5 | SCL — I2C serial clock |
| Pin 6 | AD0 — I2C address select / auxiliary logic input (per datasheet) |
Typical Applications
DS2484R+T is suitable for 7 applications: Battery-Pack Authentication, Multi-Node 1-Wire Temperature Sensing, iButton Reader Accessories, Low-Pin-Count MCU Sensor Hubs, Industrial Sensor Identification, Medical Device Accessory Authentication, Smart Home and IoT Sensor Bridges.
Battery-Pack Authentication
The DS2484R+T is a strong fit for battery-pack authentication because it lets a small-pin-count host microcontroller drive Maxim/ADI 1-Wire secure authenticators such as the DS2431, DS28E15, and DS28EC20 over its I2C bus. The bridge handles reset/presence timing and exposes an active pull-up that supplies the strong current required during EEPROM writes inside the authenticator. Operating from 1.71V to 5.25V, the part rides directly on a single-cell Li-ion rail, and the 6-pin SOT-23 footprint fits inside space-constrained battery PCBs. Drop-in same-die variants make second-sourcing easy for high-volume OEM programs.
Recommended
Multi-Node 1-Wire Temperature Sensing
For multi-node temperature chains, the DS2484R+T converts I2C commands from the host into precisely timed 1-Wire reset, read, and write slots that DS18B20 and DS1922 sensors require. Its user-adjustable tRSTL, tMSP, tW0L, and tREC timers let designers compensate for long cable runs or non-standard slaves. The integrated active pull-up supplies the strong current that DS18B20 draws during a temperature conversion, eliminating an external MOSFET. Standard and overdrive 1-Wire speeds allow fast enumeration of large sensor chains.
Recommended
iButton Reader Accessories
The DS2484R+T enables compact iButton reader accessories that need to enumerate DS1990 serial-number iButtons brought into contact with a probe. Because the bridge handles all 1-Wire timing, the host MCU only issues high-level I2C commands and reads back the 64-bit ROM ID. The SOT-23-6 package allows integration into handheld or panel-mount readers with minimal PCB area. Sleep mode minimizes standby current for battery-powered reader designs.
Recommended
Low-Pin-Count MCU Sensor Hubs
Low-pin-count microcontrollers (e.g., 8-pin or 14-pin parts) often lack a free GPIO for bit-banging 1-Wire. The DS2484R+T solves this by exposing the 1-Wire bus through a 2-wire I2C interface that any MCU can drive. The bridge offloads strict timing tolerances (tRSTL, tW0L, tREC) so the host firmware stays simple. Operating down to 1.71V lets the bridge ride on the same rail as the MCU without a level shifter.
Recommended
Industrial Sensor Identification
Industrial sensor modules frequently embed a 1-Wire ID or calibration chip that a service tool must read. The DS2484R+T lets the service tool poll the module through its I2C port without dedicating a free GPIO. Industrial temperature range (-40 C to +85 C) and RoHS compliance make it acceptable for factory-floor and field-instrument equipment. Strong ESD tolerance and a small SOT-23-6 footprint are well suited to sealed probes.
Recommended
Medical Device Accessory Authentication
Medical disposable accessories (electrodes, sensors, dosing cartridges) increasingly include 1-Wire authenticators to prevent counterfeits. The DS2484R+T bridges the host MCU to these authenticators through I2C, with the active pull-up ensuring clean communications during EEPROM writes. The small SOT-23-6 package fits inside thin-form-factor handhelds. Designers should validate that the medical end-equipment requires the appropriate regulatory certifications beyond the IC itself.
Recommended
Smart Home and IoT Sensor Bridges
Smart-home and IoT hubs often aggregate 1-Wire sensors for environmental monitoring. The DS2484R+T lets a Wi-Fi or BLE SoC drive the 1-Wire bus through I2C without needing a precise hardware timer. Sleep mode minimizes quiescent draw on battery-powered edge nodes, and the 1.71V-5.25V supply range matches both 1.8V and 3.3V SoCs. Overdrive 1-Wire mode accelerates boot-time enumeration across many nodes.
Recommended
Recommended Products Summary
Engineering reference data for DS2484R+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DS2484R+U | DS2484R+T (full reel) |
|---|---|---|---|
| Package | SOT-23-6 | SOT-23-6 - same | SOT-23-6 - same |
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Function | I2C-to-1-Wire bridge | I2C-to-1-Wire bridge | I2C-to-1-Wire bridge |
| Supply Voltage Range | 1.71 V to 5.25 V | 1.71 V to 5.25 V | 1.71 V to 5.25 V |
| I2C Speed | 100/400 kHz | 100/400 kHz | 100/400 kHz |
| 1-Wire Speed | Standard + Overdrive | Standard + Overdrive | Standard + Overdrive |
| Active Pull-Up | Yes | Yes | Yes |
| Adjustable 1-Wire Timing | Yes (tRSTL, tMSP, tW0L, tREC) | Yes (same set) | Yes (same set) |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| RoHS / Lead-Free | Yes / Yes | Yes / Yes | Yes / Yes |
Key Differentiators
- Smallest footprint 1-Wire bridge in the ADI/Maxim portfolio (vs DS2482 (SO-8))
- Adjustable 1-Wire timing registers (vs DS2482 (SO-8))
- Integrated active pull-up for high-current slaves (vs Discrete bit-bang solutions)
- Drop-in same-brand variants for high-volume manufacturing (vs DS2484R+U (Analog Devices))
Design Notes
Place a 100 nF X7R decoupling capacitor as close as possible between VDD (pin 1) and GND (pin 2) of the SOT-23-6 footprint. Keep the 1-Wire trace short and isolated from noisy switching rails; a guard trace tied to ground helps with long-cable applications. The I2C SDA/SCL traces should include 2.2 kΩ to 10 kΩ pull-ups to VDD according to bus capacitance. Avoid routing the 1-Wire line parallel to switching nodes for more than a few millimetres.
Do not omit the external pull-up resistor on the 1-Wire line - the DS2484R+T drives the line low but relies on the pull-up to return it high. For 1-Wire chains longer than a few metres or with many devices, increase the pull-up current or use the active pull-up feature for high-current slaves. Avoid operating at 5 V with long cables unless you have verified ESD and signal-integrity margins, since 1-Wire edges are not as robust as differential buses.
The DS2484R+T has user-adjustable 1-Wire timing parameters (tRSTL, tMSP, tW0L, tREC) that should be tuned to match the slowest slave on the bus. According to the Analog Devices DS2484 datasheet, increasing tRSTL improves robustness on long cables but slows enumeration. If your chain mixes standard and overdrive slaves, enumerate at standard speed first and then switch selected devices into overdrive via the appropriate configuration command.
Enable the DS2484R+T sleep mode between 1-Wire transactions to minimize quiescent current on battery-powered designs. According to the Analog Devices DS2484 datasheet, sleep mode drops the bridge into a low-Iq state until the next I2C command wakes it. Pair this with a properly sized 1-Wire pull-up so that the strong pull-up engages only during EEPROM writes or temperature conversions to avoid wasted dissipation on the host rail.
Compliance Information
RoHS and REACH compliance confirmed by Analog Devices product page and authorized distributor listings as of 2026-10-20. Halogen-free and conflict-minerals declarations not explicitly stated in the provided web data; marked unknown.
