Analog Devices Inc./Maxim Integrated MAX6664AEE+T

Overview

The MAX6664AEE+T 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, delivers open-drain PWM_OUT control at programmable frequencies up to 93.5 Hz, and operates from +3V to +5.5V supply. It is used in server CPU cooling subsystems where precise dual-zone thermal monitoring and fail-safe fan speed regulation are required.

For engineers reviewing the MAX6664AEE+T datasheet, MAX6664AEE+T pinout, MAX6664AEE+T application, or MAX6664AEE+T equivalent, this page delivers verified functional identity, QSOP-16 package mapping, SMBus 2-wire interface timing compliance, remote diode measurement architecture, and validated alternative part comparisons - all grounded in Maxim's official documentation for the MAX6664AEE+T variant.

Technical Context

The MAX6664AEE+T implements a dual-channel delta-sigma ADC architecture for simultaneous local die and remote PN-junction temperature acquisition. Its remote sensing uses a switched-current source (8–12 µA) on DXP with DXN biased at 0.65 V, supporting differential diode voltage inputs from 0.25 V to 0.95 V. The device features hard-wired CRIT0/CRIT1 pins that set power-up THERM thresholds without SMBus initialization.

It integrates a fully programmable PWM generator (8 selectable frequencies, 0.416%–3.333% duty-cycle step resolution), tachometer input with 6% accuracy and 255-count full-scale, and four independent temperature comparison engines driving INT, THERM, and (in MAX6653 only) SDL/SDR outputs. Unlike the MAX6653, the MAX6664AEE+T omits SDL and SDR pins and associated shutdown logic, retaining only INT and THERM interrupt outputs.

Key Specifications

Pinout & Package

MAX6664AEE+T is housed in a 16-pin QSOP package (5.3 mm × 10.2 mm, 0.65 mm pitch) with exposed pad for thermal dissipation. Pin functions are electrically and physically identical to MAX6663AEE but exclude SDL/SDR functionality.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar temperature monitor and PWM fan controller applications.

Compared with MAX6663AEE+T, the MAX6664AEE+T provides distinct CRIT0/CRIT1 power-up THERM set points (e.g., 100°C remote / 70°C local vs. 95°C/65°C), while both share identical real-time sensing accuracy, PWM performance, and SMBus reliability features - making MAX6664AEE+T optimal for systems needing higher initial thermal margins.

Availability

MAX6664AEE+T is available at Aetrix Electronics and suitable for server thermal management, industrial PLC cabinet cooling, and telecom base station power amplifier regulation requiring stable component supply across extended product lifecycles.

Supply support for MAX6664AEE+T 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, computing, and communications markets, with emphasis on power management, sensing, and interface solutions.

The MAX66xx family was engineered specifically for ACPI-compliant thermal monitoring and fan control in x86 platforms, delivering hardware-fail-safe defaults, SMBus robustness, and dual-zone temperature regulation without host processor dependency.

FAQ

What is the remote temperature measurement accuracy of the MAX6664AEE+T?

The MAX6664AEE+T achieves ±1°C remote temperature accuracy over the +60°C to +100°C range when measuring a properly biased remote PN junction. Outside this band, accuracy degrades to ±3°C (0°C to +100°C) and ±4°C (-25°C to +125°C), as specified in the Electrical Characteristics table. This performance is enabled by its 8–12 µA switched-current source and differential DXP/DXN architecture.

Does the MAX6664AEE+T support hardware-configurable thermal trip points at power-up?

Yes, the MAX6664AEE+T uses CRIT0 and CRIT1 pins to set non-volatile THERM and local/remote high-limit thresholds at power-on without SMBus communication. These pins decode eight combinations (e.g., GND/VCC = 100°C remote / 70°C local), providing fail-safe thermal protection during BIOS initialization or firmware crashes - a key differentiator from software-dependent alternatives like the LM96163.

Can the MAX6664AEE+T drive a 3-wire fan directly?

Yes, the MAX6664AEE+T supports 3-wire fans via its TACH/AIN pin, which accepts tachometer pulses with 6% accuracy and full-scale count of 255. The device monitors fan RPM in real time, stores speed in register 08h, and asserts FAN_FAULT on stall (FFh reading) or missing pulse detection - enabling closed-loop speed verification alongside PWM control.

What is the function of the ADD pin on the MAX6664AEE+T?

The ADD pin on the MAX6664AEE+T sets the two least-significant bits of the SMBus slave address, allowing three unique addresses (0101100, 0101101, 0101110) on a shared bus. It must be tied to VCC, GND, or left floating - not driven by logic - to avoid bus contention. This enables up to three MAX6664AEE+T devices to coexist on one SMBus segment for multi-zone monitoring.

How does the MAX6664AEE+T handle electromagnetic interference on the remote diode lines?

MAX6664AEE+T mitigates EMI on DXP/DXN through internal biasing (DXN fixed at 0.65 V), controlled current sourcing (8–12 µA), and explicit design guidance: a 2200 pF capacitor between DXP and DXN is mandatory for noise filtering, with maximum total capacitance capped at 3300 pF to prevent conversion errors from current-source slew limitations.