Analog Devices Inc./Maxim Integrated MAX6664AEE+

Overview

The MAX6664AEE+ from Maxim Integrated is an ACPI-compliant local/remote temperature sensor and PWM fan controller IC designed for thermal management in microprocessor-based systems. It measures its own die temperature (±2°C accuracy, -40°C to +125°C) and remote-PN junction temperature (±1°C from +60°C to +100°C), provides 0.125°C resolution for both channels, drives a PWM fan output with programmable frequency (11.7–93.5 Hz), and communicates via SMBus 2-wire interface. It is used in server CPU cooling subsystems where precise thermal throttling and fail-safe fan control are required.

For engineers reviewing the MAX6664AEE+ datasheet, MAX6664AEE+ pinout, MAX6664AEE+ application, or MAX6664AEE+ equivalent, key selection considerations include remote diode measurement accuracy over +60°C–+100°C, SMBus timeout compliance, THERM/INT interrupt behavior under external pull-down, PWM rise/fall time control, and absence of shutdown outputs (SDL/SDR) - distinguishing it from MAX6653AEE+.

Technical Context

The MAX6664AEE+ integrates dual delta-sigma ADCs for simultaneous local die and remote diode temperature sensing, with internal biasing (DXN at 0.65V above GND) and programmable conversion rates (0.0625–4 Hz). Its fan-control logic supports three modes: automatic (remote-temperature-driven PWM), RPM-select (tachometer-targeted), and direct PWM duty-cycle programming - all with configurable spin-up duration and fan-filter smoothing.

It implements SMBus 2.0-compliant protocols (Write Byte, Read Byte, Send Byte, Receive Byte), includes alert response address (0x19) support, and features hardware-set default trip points via CRIT0/CRIT1 pins. Unlike MAX6653, it lacks SDL/SDR shutdown outputs and does not support local shutdown set points - confirmed by pinout omission and register map (no LTSD/RTSD registers).

Key Specifications

Pinout & Package

MAX6664AEE+ is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch), RoHS-compliant and moisture-sensitive level 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar temperature-monitoring and PWM-fan-control applications.

Compared with MAX6664AEE+, MAX6663AEE+ offers identical functionality with tighter default thermal thresholds, while LM96163CIMTX/NOPB trades integrated PWM control for expanded remote-sensing capability - making MAX6664AEE+ optimal for single-CPU fan control with guaranteed SMBus robustness.

Availability

MAX6664AEE+ is available at Aetrix Electronics and suitable for server thermal management, telecom baseband cooling, and industrial PLC cabinet applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAX6664AEE+ 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, mixed-signal, and power-management ICs for demanding industrial, computing, and communications applications.

The MAX6653/MAX6663/MAX6664 product line delivers ACPI-compliant thermal monitoring and fan control for x86 and ARM-based systems - engineered specifically for reliability in high-density server and telecom thermal subsystems.

FAQ

What is the remote temperature accuracy specification for MAX6664AEE+?

The MAX6664AEE+ achieves ±1°C remote temperature measurement accuracy over the +60°C to +100°C range, as specified in the Electrical Characteristics table. This accuracy is validated across VCC = +3.3V and TA = 0°C to +100°C conditions. Outside this band - e.g., below +60°C - accuracy degrades to ±3°C (0°C to +100°C) or ±4°C (-25°C to +125°C), per the datasheet's External Temperature Error parameter.

Does MAX6664AEE+ support shutdown outputs like SDL and SDR?

No, MAX6664AEE+ does not include SDL or SDR shutdown outputs. These pins are present only on MAX6653AEE+ (pins 11 and 12), as confirmed by the Pin Description table and functional block diagram. MAX6664AEE+ shares the same 16-pin QSOP footprint but leaves pins 11 and 12 as no-connect (N.C.), and its register map omits LTSD/RTSD shutdown limit registers - confirming absence of local/remote shutdown functionality.

How does the MAX6664AEE+ handle external pull-down on the THERM pin?

When the THERM pin of MAX6664AEE+ is externally pulled low, the device asserts full-speed fan operation regardless of temperature readings - provided the mask bit for this function is not set in configuration register 1. This behavior is explicitly documented in the General Description and Pin Description sections. The status bit (bit 7 of status register 2) is set upon pull-down and cleared only by reading that register.

What SMBus address options are available for MAX6664AEE+?

MAX6664AEE+ supports three SMBus slave addresses determined by the ADD pin state: 0x54 (ADD = GND), 0x56 (ADD = floating), and 0x55 (ADD = VCC), per Table 2 in the datasheet. All addresses are 7-bit, and the device responds to the SMBus alert response address 0x19. No address conflict occurs when multiple MAX6664AEE+ units share a bus, provided ADD pins are configured uniquely.

Can MAX6664AEE+ measure temperature using a 2-wire fan's tachometer signal?

Yes, MAX6664AEE+ can repurpose the TACH/AIN pin as an analog input to measure the speed of a 2-wire fan - a feature explicitly enabled in RPM Select mode. In this configuration, the tachometer pulse train is converted to a DC-equivalent voltage via internal averaging, allowing closed-loop speed control without a dedicated tach feedback wire. This capability is detailed in the Pin Description and Functional Diagram sections.