Analog Devices Inc. ADM1032AR-REEL7-AD

Overview

ADM1032AR-REEL7-AD from ON Semiconductor is a dual-channel SMBus-compatible digital temperature monitor IC with ±1°C remote and ±3°C local sensing accuracy, 0.125°C remote resolution, and open-drain ALERT/THERM outputs for thermal management in embedded systems. It measures both ambient (on-chip) and remote diode temperature (e.g., CPU die or 2N3904/06), supports programmable limits and hysteresis, and operates from 3 V to 5.5 V.

For engineers reviewing the ADM1032AR-REEL7-AD datasheet, ADM1032AR-REEL7-AD pinout, ADM1032AR-REEL7-AD application, or ADM1032AR-REEL7-AD equivalent, key selection criteria include remote/local accuracy trade-offs, SMBus address (0x4C), THERM fail-safe behavior, and SOIC-8 package compatibility with thermal diode interface requirements.

Technical Context

The ADM1032AR-REEL7-AD implements a two-current ΔV_BE measurement technique on the remote channel to cancel transistor base-emitter voltage variation, enabling factory-trimmed ideality factor (1.008) and eliminating per-unit calibration. Its internal ADC digitizes both local and remote temperatures alternately in free-running mode, storing results in dedicated value registers.

It features fully programmable limit comparators (local/remote high/low/THERM), a status register with individual flag bits for each alarm condition, and configurable fault handling via consecutive ALERT register (1–4 out-of-limit samples required). The THERM output asserts low independently of ALERT when either local or remote THERM limit is exceeded, supporting CPU throttling or fan control without host intervention.

Key Specifications

Pinout & Package

ADM1032AR-REEL7-AD is housed in an 8-lead SOIC package (SOIC-8), with standard JEDEC MS-012AC dimensions (4.9 mm × 3.9 mm × 1.75 mm), θ_JA = 121°C/W, and Pb-free reflow peak temperature of 260°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel temperature monitoring applications.

Compared with LM94022QIMME/NOPB and MAX6642AESA+, the ADM1032AR-REEL7-AD uniquely integrates fail-safe THERM output, remote sensor diagnostics, and offset correction-making it optimal for safety-critical thermal shutdown paths where hardware autonomy matters more than marginal resolution gains.

Availability

ADM1032AR-REEL7-AD is available at Aetrix Electronics and suitable for desktop PCs, industrial PLCs, telecom line cards, and smart battery systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ADM1032AR-REEL7-AD 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power and signal management solutions, with leadership in analog, power management, and sensor technologies.

The ADM1032AR-REEL7-AD belongs to ON Semiconductor's precision thermal monitoring product line, designed specifically for real-time dual-point temperature supervision in computing, industrial, and communications infrastructure where hardware-based thermal safety is mandatory.

FAQ

What is the SMBus address of the ADM1032AR-REEL7-AD?

The ADM1032AR-REEL7-AD uses a fixed 7-bit SMBus address of 0x4C. This address is shared with the ADM1032-1 variant and differs from the ADM1032-2 (0x4D). No address pins or configuration resistors are present - the address is hardwired internally, ensuring deterministic bus enumeration in multi-device systems without address conflict risk.

Does the ADM1032AR-REEL7-AD support remote temperature sensing with discrete transistors?

Yes, the ADM1032AR-REEL7-AD supports remote sensing using discrete NPN transistors such as the 2N3904 or 2N3906, as confirmed in the General Description and Applications sections. The device applies a novel two-current ΔV_BE method that cancels process variation, enabling ±1°C accuracy without per-transistor calibration. The D+ and D− inputs are designed explicitly for this topology, with internal biasing to reject ground noise.

How does the THERM output behave when both local and remote channels exceed their limits?

The THERM output of the ADM1032AR-REEL7-AD asserts low if *either* the local or remote temperature exceeds its respective programmed THERM limit - it does not require both channels to trip simultaneously. Once asserted, THERM remains low until *both* measurements return within their THERM limits, at which point the output automatically returns high. This behavior is implemented in hardware and does not require host software intervention or register clearing.

Can the ADM1032AR-REEL7-AD operate from a 3.3 V supply?

Yes, the ADM1032AR-REEL7-AD is fully specified to operate from 3.0 V to 5.5 V, including nominal 3.3 V rails. All key parameters - including ±1°C remote accuracy, 170 μA operating current, and SMBus timing compliance - are guaranteed across this range. The undervoltage lockout threshold (2.35–2.8 V) ensures reliable reset behavior during brownout conditions common in 3.3 V systems.

What is the purpose of the offset registers (0x11 and 0x12) in the ADM1032AR-REEL7-AD?

The offset registers (0x11 high byte, 0x12 low byte) in the ADM1032AR-REEL7-AD store an 11-bit two's complement correction value applied to the raw remote temperature reading. This compensates for systematic errors introduced by series resistance in D+/D− PCB traces and differential noise coupling - critical for maintaining ±1°C accuracy in real-world layouts. The offset is added digitally post-conversion and persists across power cycles only if written during initialization.