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Analog Devices Inc./Maxim Integrated MAX6665ASA45+T
- Part No.:
- MAX6665ASA45+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Thermostats - Solid State
- Package:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Datasheet:
-
MAX6665ASA45+T.pdf
- Description:
- THERMOSTAT 45DEG ACT HI/LO 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:703
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Product details
Overview
MAX6665ASA45+T from Maxim Integrated is a factory-programmed thermal fan controller IC with a fixed +45°C activation threshold, ±1°C typical trip accuracy, 1°C/4°C/8°C pin-selectable hysteresis, 250mA internal low-side FANOUT switch, and dual open-drain overtemperature outputs (WARN at +15°C, OT at +30°C above threshold). It drives cooling fans in PC power supplies and server thermal management systems.
For engineers reviewing the MAX6665ASA45+T datasheet, MAX6665ASA45+T pinout, MAX6665ASA45+T application, or MAX6665ASA45+T equivalent, key selection criteria include its factory-set 45°C trip point, SO-EP package thermal performance, FANOUT drive capability up to 24V/250mA, low 65µA quiescent current, and integrated hysteresis configuration via HYST pin.
Technical Context
The MAX6665ASA45+T implements a monolithic die-temperature-sensing comparator with an on-chip 250mA N-channel MOSFET driver for low-side fan control. Its trip point is permanently laser-trimmed to +45°C during manufacturing and does not require external calibration.
Hysteresis is configured by the HYST pin state (floating = 1°C, GND = 4°C, VDD = 8°C), and self-heating effects-up to +7.65°C under 250mA load-must be accounted for in effective hysteresis calculation. WARN and OT outputs are active-low, open-drain, and require external pull-ups.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Fan Activation Threshold | +45°C factory-programmed; triggers FANOUT at die temperature ≥45°C |
| Threshold Accuracy | ±1°C (typ), ±3°C (max); ensures predictable fan-on timing across temperature range |
| FANOUT Drive Capability | 250mA continuous at VFANOUT < 0.6V; supports 4.5V–24V fans without external transistor |
| Supply Voltage Range | +2.7V to +5.5V; compatible with 3.3V and 5V logic rails |
| Quiescent Supply Current | 65µA (typ); enables low-power thermal monitoring in always-on systems |
| Operating Temperature Range | −40°C to +125°C; qualified for industrial and server environments |
| WARN / OT Threshold Offset | +15°C / +30°C above fan threshold; provides staged thermal response for warning and shutdown |
Pinout & Package
MAX6665ASA45+T is housed in an 8-pin SOIC with exposed paddle (SO-EP), optimized for thermal dissipation and PCB ground-plane integration. The exposed paddle is internally connected to GND and must be soldered to the system ground plane.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 GND | Ground reference | Common return for internal circuitry and FANOUT current path; connects to exposed paddle |
| 2 FORCEON | Active-low fan override input | Drives FANOUT on regardless of temperature when pulled low; enables external fan control |
| 3 HYST | Hysteresis configuration input | Floating = 1°C, GND = 4°C, VDD = 8°C; sets thermal deadband to prevent fan oscillation |
| 4 FANON | Active-high fan status indicator | Push-pull output high when FANOUT is active; signals fan operational state to host controller |
| 5 OT | Active-low overtemperature output | Open-drain signal asserted at +30°C above threshold; used for system-level thermal shutdown |
| 6 WARN | Active-low overtemperature warning | Open-drain signal asserted at +15°C above threshold; provides early thermal alert before shutdown |
| 7 VDD | Logic supply input | +2.7V to +5.5V supply; requires local 1µF bypass capacitor to GND for noise immunity |
| 8 FANOUT | Low-side fan driver output | N-channel MOSFET drain; connects to fan cathode; sinks up to 250mA to GND |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 250mA fan switch | Eliminates need for external MOSFET, gate driver, and sense resistor in basic fan control designs |
| Factory-programmed +45°C threshold | Removes calibration step and external components; guarantees consistent thermal response across production units |
| Pin-selectable hysteresis (1°C/4°C/8°C) | Enables system-specific tuning of thermal deadband without firmware or additional logic |
| Dual overtemperature outputs (WARN/OT) | Supports two-tier thermal response: warning at +15°C, shutdown at +30°C above fan threshold |
| 65µA supply current | Minimizes standby power draw in thermally monitored systems that remain powered during idle states |
Applications
| Server CPU Thermal Management | ATX Power Supply Fan Control |
|---|---|
Use Scenario: Monitors motherboard VRM and CPU vicinity temperature to activate cooling fan before thermal throttling occurs. IC Role / Device Role / Timing Role: Die-temperature-sensing fan controller with fixed +45°C trip and staged WARN/OT outputs. Use Value: Prevents sustained CPU overheating by triggering fan at precise junction temperature, with early warning (+15°C) and hard shutdown (+30°C) signals. |
Use Scenario: Regulates cooling fan speed in desktop ATX PSUs based on internal heatsink temperature. IC Role / Device Role / Timing Role: Low-side fan driver with factory-set +45°C activation and self-heating-compensated hysteresis. Use Value: Enables reliable, component-level thermal protection without microcontroller intervention or analog feedback loops. |
| Laboratory Instrument Cooling | Industrial Card Rack Thermal Monitoring |
Use Scenario: Controls fan in precision test equipment where ambient drift must not trigger false fan activation. IC Role / Device Role / Timing Role: Fixed-threshold thermal switch with ±1°C accuracy and configurable hysteresis to reject transient thermal noise. Use Value: Ensures fan remains off during stable operation and activates only upon verified sustained temperature rise, reducing acoustic noise. |
Use Scenario: Provides fail-safe thermal oversight in multi-slot industrial backplanes with high-power modules. IC Role / Device Role / Timing Role: Standalone overtemperature monitor with dual open-drain outputs for independent warning and shutdown signaling. Use Value: Delivers deterministic thermal response across wide temperature range (−40°C to +125°C) without software dependency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar thermal fan controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM75BIMM-3/NOPB | Temperature sensor only (I²C output); no integrated fan driver or hysteresis control | Requires external MCU and MOSFET driver; suitable for programmable or multi-zone systems | Select when flexible threshold programming and digital interface are required over fixed-point simplicity |
| MAX6642AESA+ | Two remote diode inputs + local sensor; I²C interface; no integrated fan driver or FANOUT pin | Designed for multi-source thermal monitoring with host-controlled fan PWM; lacks direct drive capability | Select when monitoring multiple dies (e.g., CPU + GPU) and closed-loop PWM control is needed |
Compared with LM75BIMM-3/NOPB and MAX6642AESA+, the MAX6665ASA45+T delivers immediate, autonomous fan actuation at +45°C without firmware, communication bus, or external power stage-ideal for cost-sensitive, single-zone, fail-safe thermal protection.
Availability
MAX6665ASA45+T is available at Aetrix Electronics and suitable for server thermal management, ATX power supply fan control, and laboratory instrument cooling requiring stable component supply and guaranteed factory-programmed trip points.
Supply support for MAX6665ASA45+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, mixed-signal, and power management ICs for industrial, computing, and communications applications.
The MAX6665 series was developed specifically for autonomous, low-component-count thermal management in space-constrained systems such as servers, PSUs, and instrumentation-emphasizing factory-trimmed reliability over programmability.
FAQ
What is the exact factory-programmed temperature threshold for MAX6665ASA45+T?
The MAX6665ASA45+T has a permanently programmed fan activation threshold of +45°C, verified across production lots and guaranteed within ±3°C maximum error over −40°C to +125°C operating range. This value is laser-trimmed during wafer sort and cannot be adjusted in-circuit. The MAX6665ASA45+T's trip point remains fixed regardless of supply voltage or external loading conditions.
Can MAX6665ASA45+T drive a 24V fan directly?
Yes, the MAX6665ASA45+T's FANOUT pin supports fan supply voltages from +4.5V to +24V and can sink up to 250mA continuously. Its FANOUT output is rated for 26V absolute maximum and exhibits <0.6V saturation voltage at 250mA, enabling direct low-side switching of 24V fans without external components. Self-heating must be considered when operating at full current.
How is hysteresis configured on MAX6665ASA45+T?
Hysteresis on the MAX6665ASA45+T is set exclusively via the HYST pin: leave it unconnected for 1°C, tie it to GND for 4°C, or connect it to VDD for 8°C. This selection determines the temperature drop required after fan activation before FANOUT turns off. Effective hysteresis increases by up to +7.65°C due to self-heating under 250mA load.
What is the function of the FORCEON pin on MAX6665ASA45+T?
The FORCEON pin on MAX6665ASA45+T is an active-low input that overrides the internal thermal comparator: pulling FORCEON low forces FANOUT active regardless of die temperature, while leaving it high enables normal temperature-based operation. It also drives the FANON output high during forced operation, providing unambiguous fan status indication to the system controller.
Are WARN and OT outputs on MAX6665ASA45+T push-pull or open-drain?
Both WARN and OT outputs on MAX6665ASA45+T are active-low, open-drain terminals requiring external pull-up resistors to a logic-compatible voltage (≤+6V). They assert at +15°C and +30°C above the +45°C fan threshold respectively, and each can sink up to 20mA. Their open-drain architecture allows wired-OR connection to shared interrupt lines in multi-sensor systems.
MAX6665ASA45+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Trip Temperature Threshold:
- Hot
- Switching Temperature:
- 45°C
- Accuracy:
- ±3°C
- Current - Output (Max):
- 250mA
- Output Type:
- Open Drain, Push-Pull
- Output:
- Active High, Active Low
- Output Function:
- FanOn, /FanOut, /OverTemp, /Warn
- Selectable Hysteresis:
- Yes
- Features:
- -
- Voltage - Supply:
- 2.7 V ~ 5.5 V
- Current - Supply:
- 65µA
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-SOIC-EP
MAX6665ASA45+T FAQ
1.How can I place an order for MAX6665ASA45+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6665ASA45+T 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 MAX6665ASA45+T reliable?
The price and inventory of MAX6665ASA45+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6665ASA45+T is usually 5 days.
3.What payment methods are accepted for MAX6665ASA45+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6665ASA45+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6665ASA45+T?
MAX6665ASA45+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6665ASA45+T 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 MAX6665ASA45+T?
For technical support, including MAX6665ASA45+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6665ASA45+T requirements.
6.How does Aetrix verify that MAX6665ASA45+T is sourced from the original manufacturer or authorized distributors?
All MAX6665ASA45+T 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 MAX6665ASA45+T meets industry standards.
7.What is the process for return or replacement of MAX6665ASA45+T?
All MAX6665ASA45+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6665ASA45+T, 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 MAX6665ASA45+T part is unused and in its original packaging.
Return procedure for MAX6665ASA45+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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