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Analog Devices Inc./Maxim Integrated MAX6668AUA45
- Part No.:
- MAX6668AUA45
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Thermostats - Solid State
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX6668AUA45.pdf
- Description:
- REMOTE TEMPERATURE SWITCH
- Quantity:
- Payment:
- Shipping:
Inventory:172
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Product details
Overview
MAX6668AUA45 from Maxim Integrated is a remote-junction thermal switch with integrated +12V/250mA fan driver, factory-programmed trip threshold of +45°C, ±2.2°C max accuracy over -40°C to +125°C, and fixed 8°C hysteresis - used for autonomous fan control in notebook computers, network switches, and PC power supplies.
For engineers reviewing the MAX6668AUA45 datasheet, MAX6668AUA45 pinout, MAX6668AUA45 application, or MAX6668AUA45 equivalent, this page delivers verified electrical parameters, package mapping, thermal switching behavior, fan-drive capability, and direct alternative part comparisons - all specific to the MAX6668AUA45 variant.
Technical Context
The MAX6668AUA45 implements a dedicated analog temperature comparator that monitors voltage drop across an external diode-connected transistor (e.g., 2N3904) to infer junction temperature. It drives FANOUT as an open-drain MOSFET capable of sinking ≥250mA at ≤1V saturation when active.
Its internal circuitry includes a precision current source for DXP/DXN biasing, power-on reset (POR) at 1.0–2.0V VDD, and fixed 8°C hysteresis to prevent fan oscillation near threshold. No software or calibration is required - operation is fully autonomous upon power-up.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Fan Trip Threshold | +45°C factory-programmed; triggers FANOUT activation when remote P-N junction exceeds this value. |
| Temperature Accuracy | ±2.2°C max over +40°C to +75°C remote-junction range; ensures reliable thermal response in automotive-grade environments. |
| FANOUT Drive Capability | +12V/250mA sink; directly powers small cooling fans without external transistors or gate drivers. |
| Supply Voltage Range | +3.0V to +3.6V; compatible with 3.3V system rails and immune to typical LDO ripple. |
| Quiescent Current | 110µA typical; enables low-power thermal monitoring in always-on subsystems. |
| Hysteresis | Fixed 8°C; prevents rapid on/off cycling during slow thermal transients near trip point. |
| Operating Temperature | -40°C to +125°C; qualified for under-hood automotive and industrial embedded applications. |
Pinout & Package
MAX6668AUA45 is housed in an 8-pin µMAX package (3.0mm × 3.0mm, 0.5mm pitch), with exposed PGND pad for thermal dissipation and compact PCB footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 PGND | Power Ground | Return path for FANOUT MOSFET; must be connected to low-impedance ground plane for stable 250mA switching. |
| 2 FORCEON | Digital Control Input | Active-low override: pulling low forces FANOUT on regardless of sensed temperature. |
| 3 DXP | Current Source Positive | Biases anode of remote diode; requires 2200pF capacitor to DXN for noise immunity. |
| 4 DXN | Current Sink Negative | Connects to cathode of remote diode; internally biased to ~0.7V below DXP. |
| 5 & 7 GND | Analog Ground | Reference for internal comparator and sensor circuitry; separate from PGND to reduce noise coupling. |
| 6 VDD | Power Supply | +3.0V to +3.6V input; bypass with 1µF ceramic capacitor placed adjacent to pin. |
| 8 FANOUT | Open-Drain Fan Driver | Sinks up to 250mA; connects directly to fan's cathode or low-side switch configuration. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated +12V/250mA fan driver | Eliminates need for external MOSFET, gate driver, and current-sense resistor - reduces BOM count by ≥4 components. |
| Factory-programmed +45°C trip threshold | Guarantees consistent thermal response across production lots without trimming or firmware configuration. |
| No calibration or software required | Autonomous operation from power-up; suitable for legacy BIOS systems and microcontroller-free designs. |
| 8-pin µMAX package (3mm × 3mm) | Enables placement within 10cm of CPU or GPU die for accurate remote junction sensing with minimal trace inductance. |
| ±2.2°C max temperature error | Meets tight thermal margin requirements for fan-start timing in high-reliability computing and telecom equipment. |
Applications
| Notebook Computers | Network Switches |
|---|---|
Use Scenario: Thermal management of dual-core CPUs and chipset VRMs in space-constrained clamshell designs. IC Role / Device Role / Timing Role: Remote-junction temperature switch triggering fan activation at precisely +45°C to balance acoustics and silicon reliability. Use Value: Prevents CPU throttling by initiating airflow before junction reaches +70°C, leveraging ±2.2°C accuracy to avoid premature fan spin-up. |
Use Scenario: Cooling control for 24-port Gigabit Ethernet switches with ASICs generating >5W localized heat. IC Role / Device Role / Timing Role: Autonomous fan controller interfacing with discrete 2N3904 sensing transistor mounted adjacent to switch fabric die. Use Value: Maintains ASIC junction < +95°C under full packet load using fixed +45°C trip and 8°C hysteresis - eliminating firmware dependency. |
| PC Power Supplies | Laboratory Instruments |
Use Scenario: Overtemperature protection for 80 PLUS Gold-rated ATX PSUs with synchronous rectifiers and LLC resonant controllers. IC Role / Device Role / Timing Role: Direct fan drive via FANOUT pin, activated when MOSFET heatsink temperature exceeds +45°C measured through remote diode. Use Value: Ensures continuous convection cooling during sustained 100% load tests without microcontroller intervention or polling overhead. |
Use Scenario: Thermal safety interlock in benchtop oscilloscopes and spectrum analyzers with FPGA-based signal processing modules. IC Role / Device Role / Timing Role: Standalone thermal switch monitoring FPGA junction via on-die diode, forcing fan-on if ambient exceeds +45°C during extended calibration runs. Use Value: Guarantees instrument stability by preventing FPGA thermal runaway - critical for sub-ppm measurement repeatability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar remote-junction thermal switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6668AUA50 | Same package and architecture, but +50°C factory-trip threshold instead of +45°C. | Used where higher thermal margin is acceptable before fan activation, e.g., in lower-power SoC platforms. | Select MAX6668AUA50 only if system thermal design targets fan start at +50°C - not a drop-in replacement for +45°C requirement. |
| LM57BISD-5.0/NOPB | Adjustable trip via external resistor divider; ±3°C accuracy; no integrated fan driver - requires external MOSFET. | Suitable for designs needing programmable thresholds or multi-zone thermal control with shared sensing infrastructure. | Choose LM57BISD-5.0/NOPB when flexibility in trip point outweighs BOM simplicity - MAX6668AUA45 offers lower component count and guaranteed +45°C accuracy. |
Compared with MAX6668AUA50 and LM57BISD-5.0/NOPB, the MAX6668AUA45 uniquely delivers factory-trimmed +45°C switching with integrated 250mA fan drive in a space-optimized µMAX package - reducing layout complexity and qualification effort for fixed-threshold, fan-integrated thermal management.
Availability
MAX6668AUA45 is available at Aetrix Electronics and suitable for notebook computers, network switches, and PC power supplies requiring stable component supply across automotive-grade temperature ranges and long product lifecycles.
Supply support for MAX6668AUA45 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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing applications.
The MAX6668/MAX6670 product line was designed specifically for autonomous, software-free thermal management in space-constrained systems - delivering factory-programmed precision and integrated power switching in ultra-small packages.
FAQ
What is the exact factory-programmed temperature threshold for MAX6668AUA45?
The MAX6668AUA45 has a factory-programmed remote-junction temperature trip threshold of +45°C, with ±2.2°C maximum error over the +40°C to +75°C sensing range. This value is laser-trimmed during production and cannot be adjusted externally - it is fixed for the MAX6668AUA45 variant specifically.
Does MAX6668AUA45 include an integrated fan driver, and what are its electrical limits?
Yes, the MAX6668AUA45 integrates a +12V-tolerant, open-drain FANOUT power MOSFET capable of sinking ≥250mA with ≤1V saturation voltage at 250mA. It supports fan supply voltages up to +12V nominal (15V absolute max), and requires connection to PGND for proper power return path handling.
Can MAX6668AUA45 be used with a discrete transistor as the remote temperature sensor?
Yes, the MAX6668AUA45 is explicitly designed to interface with discrete diode-connected transistors such as the 2N3904 or CMPT3904. The DXP/DXN pins provide matched current biasing, and a 2200pF capacitor between them is recommended for noise filtering in electrically noisy environments like motherboard layouts.
What is the hysteresis setting for MAX6668AUA45, and is it configurable?
The MAX6668AUA45 features a fixed 8°C hysteresis - it is not user-configurable. Unlike the MAX6670 family, which uses the HYST pin for 4°C/8°C/12°C selection, the MAX6668 series embeds hysteresis internally. This simplifies design for applications where consistent, unadjusted thermal recovery behavior is required.
What package type and dimensions does MAX6668AUA45 use?
The MAX6668AUA45 is packaged in an 8-pin µMAX (also labeled uSOP), measuring 3.0mm × 3.0mm with 0.5mm lead pitch and an exposed PGND pad. Its footprint matches JEDEC MO-220 standard, and mechanical drawings confirm body height of 0.8mm and thermal pad dimensions of 2.2mm × 2.2mm.
MAX6668AUA45 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Trip Temperature Threshold:
- Hot
- Switching Temperature:
- 45°C
- Accuracy:
- ±2.2°C
- Current - Output (Max):
- 250mA
- Output Type:
- Open Drain
- Output:
- Active Low
- Output Function:
- /FanOut
- Selectable Hysteresis:
- Yes
- Features:
- -
- Voltage - Supply:
- 3 V ~ 3.6 V
- Current - Supply:
- 110µA
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-µMAX
MAX6668AUA45 FAQ
1.How can I place an order for MAX6668AUA45 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6668AUA45 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 MAX6668AUA45 reliable?
The price and inventory of MAX6668AUA45 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6668AUA45 is usually 5 days.
3.What payment methods are accepted for MAX6668AUA45?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6668AUA45 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6668AUA45?
MAX6668AUA45 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6668AUA45 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 MAX6668AUA45?
For technical support, including MAX6668AUA45 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6668AUA45 requirements.
6.How does Aetrix verify that MAX6668AUA45 is sourced from the original manufacturer or authorized distributors?
All MAX6668AUA45 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 MAX6668AUA45 meets industry standards.
7.What is the process for return or replacement of MAX6668AUA45?
All MAX6668AUA45 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6668AUA45, 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 MAX6668AUA45 part is unused and in its original packaging.
Return procedure for MAX6668AUA45:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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