Analog Devices Inc./Maxim Integrated DS18B20+T&R

Overview

DS18B20+T&R from Maxim Integrated is a programmable-resolution 1-Wire digital thermometer IC with ±0.5°C accuracy from −10°C to +85°C, −55°C to +125°C operating range, and parasite-power capability via DQ pin - enabling distributed temperature sensing in HVAC controls, industrial monitoring, and embedded thermal management systems.

For engineers reviewing the DS18B20+T&R datasheet, DS18B20+T&R pinout, DS18B20+T&R application, or DS18B20+T&R equivalent, this page delivers verified electrical specs, SO-8/µSOP/TO-92 package mapping, alarm-trigger EEPROM configuration, 1-Wire timing compliance, and real-world multidrop deployment guidance - all grounded in Maxim's official Rev 6 datasheet (19-7487).

Technical Context

The DS18B20+T&R implements a fully integrated 1-Wire interface using open-drain DQ with internal pullup control logic and parasitic power circuitry (CPP capacitor), eliminating external supply requirements in two-wire configurations. Its 64-bit ROM enables bus-level device addressing without address decoding hardware.

Temperature conversion uses a delta-sigma ADC with user-selectable 9–12-bit resolution (0.0625°C to 0.5°C LSB), stored in a 2-byte sign-extended two's complement register; alarm thresholds (TH/TL) and configuration data reside in nonvolatile EEPROM with 50k write cycles and 10-year retention at −55°C to +55°C.

Key Specifications

Pinout & Package

DS18B20+T&R is supplied in tape-and-reel format and available in three package variants: 8-pin SO (150 mils), 8-pin µSOP, and 3-pin TO-92. Pin functions are identical across packages; only physical layout differs. The +T&R suffix denotes tape-and-reel packaging for automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital thermometer applications.

Compared with MAX31820MUA+, DS18B20+T&R offers lower unit cost and broader ecosystem support but requires host-side CRC computation; versus DS1820Z+, it delivers superior accuracy, alarm intelligence, and EEPROM configurability - making it the preferred choice for modern thermal management systems requiring reliability and feature depth.

Availability

DS18B20+T&R is available at Aetrix Electronics and suitable for HVAC environmental controls, industrial equipment thermal protection, and consumer appliance temperature feedback requiring stable component supply across production lifecycles.

Supply support for DS18B20+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

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for industrial, medical, and communications applications - emphasizing robustness, low power, and system-level integration.

The DS18B20+T&R belongs to Maxim's 1-Wire sensor family, engineered specifically for distributed, low-wiring-count temperature monitoring in harsh or space-constrained environments - balancing accuracy, configurability, and bus scalability.

FAQ

What is the maximum number of DS18B20+T&R sensors supported on a single 1-Wire bus?

The DS18B20+T&R uses a unique 64-bit ROM address for device identification, allowing theoretically unlimited sensors on one bus. Practical limits depend on bus capacitance and pullup strength; tested deployments reliably support 50–100 units with 4.7kΩ pullup and proper termination. Each DS18B20+T&R must be individually addressed via its ROM code during initialization or matched using the Match ROM [55h] command.

Does DS18B20+T&R require an external power supply, or can it operate in parasite power mode?

The DS18B20+T&R supports both modes: external VDD supply (3.0–5.5V) or parasite power via the DQ pin. In parasite mode, VDD must be grounded, and a strong pullup (e.g., MOSFET-switched rail) is mandatory during temperature conversions to supply peak current (1.5mA). DS18B20+T&R achieves full functionality in either configuration - parasite mode reduces wiring to two conductors (DQ+GND), ideal for distributed sensing.

How does the alarm function work in DS18B20+T&R, and how is it configured?

The DS18B20+T&R features nonvolatile TH and TL registers storing user-defined Celsius thresholds. After each temperature conversion, the result is compared to these values; if outside bounds, an internal alarm flag is set. Configuration is done via Write Scratchpad [4Eh] and Copy Scratchpad [48h] commands. The Alarm Search [ECh] command then identifies all flagged DS18B20+T&R units on the bus - enabling rapid fault isolation without individual polling.

What is the conversion time for DS18B20+T&R at different resolution settings?

DS18B20+T&R conversion time scales directly with resolution: 93.75 ms at 9-bit, 187.5 ms at 10-bit, 375 ms at 11-bit, and 750 ms at 12-bit (default). These values are specified at VDD = 5V and reflect total time from Convert T [44h] command issuance to valid data in the scratchpad. Parasite power mode requires strong pullup activation within 10 µs of the command and sustained for the full duration.

Is DS18B20+T&R RoHS-compliant and lead-free?

Yes, DS18B20+T&R is RoHS-compliant and lead-free per Maxim Integrated's product documentation (Rev 6, 2019). It meets JEDEC J-STD-020 moisture sensitivity level (MSL) requirements for SO and µSOP packages, and is qualified for reflow soldering per industry-standard profiles. The TO-92 variant also complies with lead-free exemptions applicable to through-hole components.