Analog Devices Inc. ADT7486AARMZ-R7

Overview

ADT7486AARMZ-R7 from onsemi is a dual remote digital temperature sensor IC with Simple Serial Transport (SST) interface, monitoring one on-chip and two external diode-based temperatures (e.g., CPU/GPU), featuring ±1.0°C remote accuracy over −40°C to +125°C, 0.016°C resolution, and 3.3 V ±10% supply operation - deployed in PC motherboard thermal management systems.

For engineers reviewing the ADT7486AARMZ-R7 datasheet, ADT7486AARMZ-R7 pinout, ADT7486AARMZ-R7 application, or ADT7486AARMZ-R7 equivalent, key selection criteria include SST Rev 1 compliance, dual-remote-diode support, 10-pin MSOP package, fixed-address configuration via ADD0/ADD1 pins, and series resistance cancellation up to 1.5 kΩ.

Technical Context

The ADT7486AARMZ-R7 implements a switched-current delta-V_BE measurement architecture across three current levels (I, N₁×I, N₂×I) to reject series resistance errors and enable accurate remote diode sensing. It performs round-robin conversions: local (12 ms), remote 1 (38 ms), and remote 2 (38 ms), completing full cycle in ≤50 ms with averaging enabled.

As an SST Rev 1-compliant fixed-address client, it uses bidirectional single-wire communication with programmable target addresses (0x48–0x50) selected by ADD0/ADD1 states (low/floating/high), and supports command set including GetAllTemps (0x00, 6-byte response), GetExt2Temp (0x02), and SetExt2Offset (0xe1) - all using little-endian 16-bit two's complement temperature format.

Key Specifications

Pinout & Package

ADT7486AARMZ-R7 is housed in a Pb-free 10-lead MSOP package (Case 846AC), 3.0 mm × 3.0 mm × 1.0 mm profile, optimized for space-constrained motherboard layouts near CPU sockets or VRMs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-remote temperature sensing applications.

Compared with ADT7486AARMZ-R7, ADT7484AARMZ-RL reduces channel count and footprint but sacrifices GPU/chipset monitoring capability, while LM95235CIMM/NOPB offers interface flexibility at the cost of SST interoperability and slightly lower accuracy - making ADT7486AARMZ-R7 optimal for SST-native PC thermal architectures.

Availability

ADT7486AARMZ-R7 is available at Aetrix Electronics and suitable for PC motherboard design, GPU thermal management, and industrial embedded control requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for ADT7486AARMZ-R7 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation, delivering silicon solutions for automotive, industrial, cloud, and intelligent devices.

The ADT7486AARMZ-R7 belongs to onsemi's precision analog temperature sensor product line, engineered specifically for PC platform thermal management with SST interface compatibility and robust noise immunity in high-density digital environments.

FAQ

What is the primary function of the ADT7486AARMZ-R7 in a PC platform?

The ADT7486AARMZ-R7 serves as a dual-channel digital temperature sensor that monitors both the host processor's internal die temperature and two external thermal diodes - typically located on the CPU and GPU. It communicates these measurements over a single-wire Simple Serial Transport (SST) bus to the platform controller hub, enabling real-time thermal management, fan control, and dynamic performance scaling in desktop and workstation motherboards.

How does the ADT7486AARMZ-R7 handle noise on remote diode lines?

The ADT7486AARMZ-R7 mitigates noise through differential sensing (D1+/D1−, D2+/D2−), internal biasing of the negative input above ground, 65 kHz low-pass filtering, chopper-stabilized amplification, and 300 mV_p-p noise immunity. Layout best practices - such as parallel routing with guard traces, twisted-pair cabling beyond 8 inches, and local 0.1 µF bypassing - further ensure ±1.0°C accuracy in electrically noisy PC environments.

Can the ADT7486AARMZ-R7 be used with discrete transistors instead of integrated diodes?

Yes, the ADT7486AARMZ-R7 supports discrete NPN or PNP transistors as remote sensors: for NPN, connect emitter to D1− and base to D1+; for PNP, connect base to D1− and emitter to D1+. The device automatically detects open/short circuits and returns 0x8000. Series resistance cancellation up to 1.5 kΩ remains active, preserving accuracy regardless of transistor lead length or PCB trace resistance.

What SST address options are available for the ADT7486AARMZ-R7?

The ADT7486AARMZ-R7 supports nine fixed SST target addresses (0x48 to 0x50) determined by the logic states of ADD0 and ADD1 pins: low, floating, or high. For example, ADD1 = low and ADD0 = high selects address 0x4A. This eliminates software enumeration overhead and ensures deterministic communication in multi-sensor SST buses without address conflict.

Does the ADT7486AARMZ-R7 require external components for basic operation?

Yes - a 0.1 µF ceramic bypass capacitor must be placed close to the VCC and GND pins, and a pull-up resistor (typically 4.7 kΩ) is required on the SST line to 3.3 V. No external passive components are needed for temperature conversion, but optional RC filters (e.g., 1 nF capacitor between D1+ and D1−) may be added in extremely noisy environments per layout guidelines.