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Analog Devices Inc./Maxim Integrated MAX1669EEE
- Part No.:
- MAX1669EEE
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Thermal Management
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
MAX1669EEE.pdf
- Description:
- IC FAN CTRLR W/SENSOR 16-QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,682
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Product details
Overview
MAX1669EEE from Maxim Integrated is a fan controller and remote temperature sensor IC with SMBus 2-wire serial interface, integrating an 8-bit ADC for diode-based temperature measurement (±3°C accuracy, -40°C to +125°C), programmable PWM fan control (20Hz–160Hz), and DAC output mode. It supports remote sensing via a diode-connected transistor (e.g., 2N3906), delivers latched ALERT and active-low OVERT thermostat outputs, and operates from +3V to +5.5V - used in Pentium® CPU cooling and server thermal management.
For engineers reviewing the MAX1669EEE datasheet, MAX1669EEE pinout, MAX1669EEE application, or MAX1669EEE equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with documented functional differences, and supply support for industrial embedded and compute thermal control designs.
Technical Context
The MAX1669EEE implements a switched-current source front end with integrating ADC architecture for remote diode temperature measurement, delivering 8-bit resolution and ±3°C accuracy over -40°C to +125°C without calibration. Its independent fan control block supports two mutually exclusive output modes: low-frequency PWM (20Hz–160Hz, sync-capable up to 400kHz) or high-impedance DAC (0–0.94·VCC, 4-bit controlled).
SMBus communication uses standard protocols (write/read byte, send/receive byte) with register-mapped access to temperature data, alarm thresholds (THIGH/TLOW/TCRIT), configuration, duty/frequency registers, and status flags. Diode fault detection (open/short) and overrange reporting (+127°C) are hardware-verified; ALERT is latched and cleared only by reading the Alert Response address (0001100b), while OVERT self-clears with 5°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Remote Temp Accuracy | ±3°C (–40°C to +125°C, no calibration needed for 2N3906-type diodes) |
| FAN Output Modes | PWM (20–160Hz, sync input up to 400kHz) or DAC (0–0.94·VCC, 4-bit resolution) |
| Supply Voltage Range | +3V to +5.5V - compatible with standard logic and fan power rails |
| Standby Supply Current | 3µA - enables ultra-low-power thermal monitoring during system sleep |
| SMBus Interface | 2-wire, DC–100kHz, supports Alert Response protocol for multi-device interrupt arbitration |
| Temperature Resolution | 1°C LSB (7-bit + sign, two's complement format) |
| Diode Fault Detection | Hardware-checked open/short/DXP-DXN short at conversion start; returns +127°C on fault |
Pinout & Package
MAX1669EEE is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.635mm pitch), designed for compact placement adjacent to SLOT1 connectors in desktop/server motherboards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| I/O1 | General-purpose open-drain I/O | Configurable for fan presence detection, chassis intrusion sensing, or LED/MOSFET drive |
| OVERT | Active-low open-drain thermostat output | Self-clearing interrupt triggered at TCRIT; enables hardware fan override independent of host software |
| ALERT | Active-low open-drain SMBus alert | Latched interrupt for THIGH/TLOW crossings or diode faults; cleared only by reading Alert Response address |
| SMBDATA | Open-drain SMBus data line | Bi-directional serial data path supporting standard SMBus protocols and Alert Response arbitration |
| SMBCLK | SMBus clock input | DC–100kHz clock input; static design allows slow operation but violates SMBus spec below 10kHz |
| PGND | Power ground reference | Separate from AGND to isolate digital switching noise from analog measurement path |
| FAN | Fan-control logic output | Swings PGND-to-VCC in PWM mode; PGND-to-0.94·VCC in DAC mode - requires external driver for brushless DC fans |
| SYNC | Oscillator synchronization input | Accepts 140–400kHz external clock to align FAN PWM timing with system clocks or reduce EMI |
| VCC | Supply voltage input | +3V to +5.5V main supply; requires 0.1µF bypass capacitor to AGND per layout guidelines |
| I/O2 | General-purpose open-drain I/O | Second GPIO for redundant fan monitoring or auxiliary system signaling |
| ADD0–ADD2 | SMBus slave address select | 3-pin binary encoding (up to 8 unique addresses) for multi-device SMBus bus sharing |
| AGND | Analog ground reference | Isolated return for DXP/DXN, VCC bypass, and internal ADC - must be star-connected to minimize noise |
| DXP | Remote diode positive terminal input | Combined current source and ADC+; requires 2200pF capacitor to DXN for noise filtering |
| DXN | Remote diode negative terminal input | Combined current sink and ADC−; internally biased ~0.7V above AGND for differential measurement |
Key Features
| Feature | Design Value |
|---|---|
| Write-once configuration protection | Prevents accidental reprogramming of critical settings (e.g., address, alarm limits) after initial setup |
| Programmable under/overtemperature alarms | Independent THIGH/TLOW/TCRIT registers with POR defaults (+127°C, –55°C, +100°C) enable immediate thermal safety without host initialization |
| Flexible fan interface (PWM or DAC) | Software-selectable output mode eliminates need for external DAC or PWM generator - reduces BOM count |
| Remote diode fault detection | Hardware-level open/short diagnosis at conversion start ensures reliable thermal feedback before fan activation |
| SMBus Alert Response support | Enables multi-slave interrupt arbitration using standardized broadcast address (0001100b), simplifying host firmware |
Applications
| Pentium® CPU Cooling | Desktop Computers |
|---|---|
Use Scenario: Real-time junction temperature monitoring and closed-loop fan speed control for Intel Pentium processors in ATX motherboards. IC Role / Device Role / Timing Role: Remote temperature sensor and SMBus-addressable fan controller - replaces thermistor + discrete logic with integrated analog front-end and digital interface. Use Value: Eliminates manual calibration and reduces thermal response latency vs. analog solutions; ±3°C accuracy ensures safe CPU throttling margins. |
Use Scenario: Multi-zone thermal management across CPU, GPU, and chipset in consumer desktop platforms. IC Role / Device Role / Timing Role: SMBus slave device providing remote temperature readings and fan command execution - coordinated by system management controller. Use Value: Two GPIO pins (I/O1/I/O2) allow simultaneous fan presence verification and chassis intrusion detection, improving system reliability. |
| Notebook Computers | Servers |
Use Scenario: Compact thermal regulation in space-constrained notebook baseboards with limited PCB area near CPU socket. IC Role / Device Role / Timing Role: Low-profile QSOP-packaged sensor/controller enabling direct mounting adjacent to SLOT1 - minimizes trace length for diode sensing. Use Value: 3µA standby current extends battery life during suspend states; DAC mode supports linear fan control for ultra-quiet acoustic profiles. |
Use Scenario: Redundant thermal supervision in dual-socket server motherboards with multiple fan zones and fail-safe override. IC Role / Device Role / Timing Role: Hardware thermostat (OVERT) provides autonomous fan activation when host BMC loses communication - prevents thermal shutdown. Use Value: Self-clearing OVERT with 5°C hysteresis avoids oscillation; ALERT latching ensures no thermal interrupts are missed during BMC polling intervals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fan controller and remote temperature sensor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX1617AEEE+ | 8-bit remote temp sensor only - no integrated fan control output; SMBus-compatible register map but lacks FAN, SYNC, OVERT pins | Requires external fan driver circuitry; suitable where host MCU handles PWM generation | Select when fan control is implemented in software or separate driver IC; not drop-in for MAX1669EEE's integrated actuation |
| LM92CIMM/NOPB | 12-bit remote temp sensor with ALERT output only - no FAN output, no OVERT, no GPIOs; higher resolution (±0.25°C) but no fan interface | Used for precision monitoring only; fan speed must be managed externally via PWM generator or DAC | Choose for higher-accuracy thermal logging where fan control is handled elsewhere; incompatible pinout and missing control features |
Compared with MAX1669EEE, MAX1617AEEE+ provides identical SMBus register compatibility and remote sensing but omits all fan actuation hardware, while LM92CIMM/NOPB offers superior temperature resolution but no fan interface whatsoever - making MAX1669EEE uniquely suited for integrated thermal management with autonomous hardware override capability.
Availability
MAX1669EEE is available at Aetrix Electronics and suitable for Pentium® CPU cooling, desktop computers, notebook computers, servers, and workstations requiring stable component supply and long-term thermal management continuity.
Supply support for MAX1669EEE 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 computing, industrial, and communications systems - emphasizing integration, low power, and robustness.
The MAX1669EEE belongs to Maxim's thermal management product line, engineered specifically for PC/server motherboard applications requiring combined remote temperature sensing and SMBus-controllable fan actuation in a single QSOP package.
FAQ
What is the remote temperature accuracy of the MAX1669EEE over its full operating range?
The MAX1669EEE achieves ±3°C remote temperature accuracy from –40°C to +125°C when used with a diode-connected transistor such as the 2N3906, with no calibration required. This specification is guaranteed for transistors with ideality factor m = 1.013; deviations in m increase error per the formula ∆T = k·(m–1.013)/(273.15+TR). The MAX1669EEE's internal ADC and biasing ensure consistent performance across manufacturing lots.
How does the MAX1669EEE handle diode connection faults, and what happens to the temperature reading when a fault occurs?
The MAX1669EEE performs automatic diode fault detection at the start of each conversion cycle, identifying open-circuit, short-to-GND, or DXP-to-DXN short conditions. When a fault is detected, the device returns a +127°C reading and asserts the ALERT output. The fault status is reflected in the status byte register (RSTAT), and the condition persists until the next valid conversion - meaning the MAX1669EEE will not report false temperatures during fault states.
Can the MAX1669EEE operate in both PWM and DAC fan control modes simultaneously?
No, the MAX1669EEE supports only one fan output mode at a time. Setting the PWM frequency register (RFREQ/WFREQ) to code 1111b switches the FAN pin to DAC mode (0–0.94·VCC), while any other 4-bit code configures it for PWM operation (20Hz–160Hz). The mode selection is mutually exclusive and software-controlled - the MAX1669EEE does not allow concurrent PWM and DAC outputs on the same FAN pin.
What is the function of the OVERT output on the MAX1669EEE, and how is its behavior configured?
The OVERT output on the MAX1669EEE is an active-low, open-drain thermostat signal that activates when the measured temperature equals or exceeds the TCRIT threshold. It is self-clearing with 5°C hysteresis (resets when temp ≤ TCRIT – 5°C) and can be polarity-inverted via the configuration register. When enabled, OVERT forces the FAN output to VCC independently of software commands - providing hardware-level fan override if the host system fails, a critical safety feature in the MAX1669EEE.
Does the MAX1669EEE require external components for basic operation, and which ones are mandatory?
Yes, the MAX1669EEE requires three mandatory external components: a 0.1µF ceramic capacitor between VCC and AGND for supply decoupling; a 2200pF capacitor between DXP and DXN for remote diode noise filtering; and pull-up resistors (typically 4.7kΩ) on SMBCLK and SMBDATA for proper SMBus operation. Additional components - such as pull-ups on I/O1/I/O2 or a series resistor on FAN - depend on system-level interface requirements but are not required for core MAX1669EEE functionality.
MAX1669EEE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Fan Control, Temp Monitor
- Sensor Type:
- External
- Sensing Temperature:
- -40°C ~ 125°C
- Accuracy:
- ±5°C(Max)
- Topology:
- ADC, Comparator, Multiplexer, Register Bank
- Output Type:
- SMBus
- Output Alarm:
- Yes
- Output Fan:
- Yes
- Voltage - Supply:
- 3V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QSOP
MAX1669EEE FAQ
1.How can I place an order for MAX1669EEE through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1669EEE on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX1669EEE reliable?
The price and inventory of MAX1669EEE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1669EEE is usually 5 days.
3.What payment methods are accepted for MAX1669EEE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1669EEE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1669EEE?
MAX1669EEE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1669EEE order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX1669EEE?
For technical support, including MAX1669EEE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1669EEE requirements.
6.How does Aetrix verify that MAX1669EEE is sourced from the original manufacturer or authorized distributors?
All MAX1669EEE products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX1669EEE meets industry standards.
7.What is the process for return or replacement of MAX1669EEE?
All MAX1669EEE units undergo pre-shipment inspection (PSI). If there is an issue with MAX1669EEE, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX1669EEE part is unused and in its original packaging.
Return procedure for MAX1669EEE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX1669EEE Tags
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EMC2101-ACZL-TR
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EMC2101-R-ACZL-TR
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SE98ATP,547
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AMC6821SDBQR
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