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Analog Devices Inc./Maxim Integrated MAX6665ASA70
- Part No.:
- MAX6665ASA70
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Thermostats - Solid State
- Package:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Datasheet:
-
MAX6665ASA70.pdf
- Description:
- FAN CONTROLLER
- Quantity:
- Payment:
- Shipping:
Inventory:202
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Product details
Overview
MAX6665ASA70 from Maxim Integrated is a factory-programmed thermal fan controller IC with fixed +70°C activation threshold, ±3°C max trip accuracy, 8°C pin-selectable hysteresis, 250mA internal FET driver, and dual open-drain overtemperature outputs (WARN at +15°C, OT at +30°C above threshold). It drives cooling fans up to 24V/250mA in PC power supplies and server thermal management.
For engineers reviewing the MAX6665ASA70 datasheet, MAX6665ASA70 pinout, MAX6665ASA70 application, or MAX6665ASA70 equivalent, this page delivers verified thermal control parameters, SO-EP package details, hysteresis configuration logic, supply current behavior across temperature, and real-world fan-on timing implications for fail-safe system shutdown design.
Technical Context
The MAX6665ASA70 integrates a precision bandgap temperature sensor, comparator with programmable hysteresis via HYST pin states (floating = 1°C, GND = 4°C, VDD = 8°C), and a low-RDS(ON) N-channel MOSFET driver switching up to 250mA at ≤0.6V drop. Its FANOUT output operates as a low-side switch referenced to GND.
Two independent open-drain outputs-WARN (active-low at TTH +15°C) and OT (active-low at TTH +30°C)-provide staged thermal alerts without external components. The FANON push-pull indicator mirrors FANOUT state, while FORCEON enables external override of thermal control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Fan Activation Threshold | +70°C factory-programmed; triggers FANOUT at die temperature ≥70°C, enabling precise thermal setpoint for high-temperature environments. |
| Threshold Accuracy | ±3°C maximum error; ensures reliable fan engagement within defined thermal safety margin for industrial-grade systems. |
| Hysteresis Options | Pin-selectable 1°C / 4°C / 8°C; prevents fan oscillation during marginal temperature transitions; 8°C selected by tying HYST to VDD. |
| FANOUT Drive Capability | 250mA continuous at VFANOUT ≤ 0.6V; supports standard 5–24V cooling fans without external transistor or heatsink. |
| Supply Current | 65µA typical at +25°C; enables low-power thermal monitoring in always-on subsystems without significant battery drain. |
| Operating Voltage Range | +2.7V to +5.5V on VDD; compatible with 3.3V and 5V logic rails; fan supply independent (4.5V–24V). |
| Temperature Range | −40°C to +125°C ambient; rated for under-hood, server rack, and industrial enclosure deployment. |
Pinout & Package
MAX6665ASA70 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.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1, Exposed Paddle) | Ground reference | Common return for VDD, FANOUT, and internal FET; exposed paddle must be soldered to PCB ground plane for thermal and electrical stability. |
| FORCEON (Pin 2) | Logic input | Active-low override: pulling low forces FANOUT on regardless of temperature; enables firmware-controlled fan activation. |
| HYST (Pin 3) | Hysteresis select | Three-state input: floating = 1°C, GND = 4°C, VDD = 8°C; sets thermal deadband to prevent chatter near trip point. |
| FANON (Pin 4) | Push-pull status output | Active-high indicator synchronized with FANOUT state; drives LEDs or microcontroller GPIO without pull-up. |
| OT (Pin 5) | Open-drain alarm | Active-low at TDIE ≥ TTH +30°C; signals critical overtemperature requiring immediate system shutdown. |
| WARN (Pin 6) | Open-drain warning | Active-low at TDIE ≥ TTH +15°C; provides early thermal alert before critical failure, allowing graceful throttling. |
| VDD (Pin 7) | Logic supply | +2.7V to +5.5V input; requires local 1µF tantalum bypass capacitor to GND for noise immunity during fan switching. |
| FANOUT (Pin 8) | Low-side fan driver | N-channel MOSFET output; connects to fan cathode/ground side; fan anode connects directly to 4.5–24V supply. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 250mA fan switch | Eliminates need for external MOSFET, gate driver, and current-sense resistor-reducing BOM count and layout area. |
| Factory-set +70°C trip point | Guarantees consistent thermal response without calibration; ideal for applications where ambient or component temperature exceeds 60°C. |
| Dual-stage overtemperature signaling | WARN and OT outputs enable tiered response: throttling at +15°C offset, hard shutdown at +30°C offset-improving system reliability. |
| 65µA quiescent supply current | Minimizes standby power in always-on thermal monitors; supports energy-sensitive embedded and portable designs. |
| SO-EP package with thermal paddle | 51°C/W junction-to-board thermal resistance (with EP soldered); maintains safe die temperature even under full 250mA fan load. |
Applications
| Server Rack Thermal Management | Industrial PC Power Supply |
|---|---|
Use Scenario: Monitoring CPU and VRM heat in 1U/2U rack servers with multiple high-speed fans. IC Role / Device Role / Timing Role: Die-temperature-sensing fan controller that activates cooling when local board temperature reaches +70°C. Use Value: Prevents thermal throttling and processor lockup by ensuring fan engagement before critical junction temperatures are reached. | Use Scenario: Regulating airflow in enclosed ATX or custom industrial PSUs operating continuously at elevated ambient temperatures. IC Role / Device Role / Timing Role: Standalone thermal supervisor driving 12V/250mA blower fans based on internal die temperature. Use Value: Enables compact, component-minimized PSU designs with fail-safe thermal protection independent of host controller. |
| Notebook Base Heat Dissipation | Laboratory Instrument Enclosure Cooling |
Use Scenario: Managing GPU and chipset heat in thin-and-light notebooks with constrained airflow and passive heatsinks. IC Role / Device Role / Timing Role: Low-power thermal switch triggering fan only when baseplate temperature exceeds +70°C-reducing acoustic noise during light workloads. Use Value: Extends battery life and improves user experience via intelligent, threshold-based fan activation instead of constant rotation. | Use Scenario: Maintaining stable internal temperature in benchtop oscilloscopes, spectrum analyzers, or environmental test chambers. IC Role / Device Role / Timing Role: Precision thermal monitor with WARN/OT outputs interfacing to instrument microcontroller for graded thermal response. Use Value: Ensures measurement accuracy and component longevity by preventing drift caused by internal temperature excursions beyond +70°C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar thermal fan control applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM57CISD-70/NOPB | Adjustable threshold via external resistor divider; ±2.5°C accuracy; no integrated FET-requires external driver. | Supports variable trip points but adds complexity and board space; lacks WARN/OT outputs. | Select when flexible threshold tuning is required and external drive capability is acceptable. |
| MAX6642AUB70+ | Same +70°C threshold; I²C interface; 12-bit temperature readback; no integrated fan driver-requires external MOSFET. | Enables closed-loop thermal telemetry but increases firmware overhead and component count. | Select when digital temperature monitoring and adaptive fan speed control are needed alongside fixed-threshold safety. |
Compared with LM57CISD-70/NOPB and MAX6642AUB70+, the MAX6665ASA70 delivers plug-and-play thermal protection with zero external components, built-in 250mA drive, and dual-stage alarms-making it optimal for cost-sensitive, space-constrained, and safety-critical fan-on-demand applications.
Availability
MAX6665ASA70 is available at Aetrix Electronics and suitable for server rack thermal management, industrial PC power supplies, and laboratory instrument enclosure cooling requiring stable component supply, long-term lifecycle support, and guaranteed factory-programmed thresholds.
Supply support for MAX6665ASA70 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 MAX6665ASA70 belongs to Maxim's thermal management product line, engineered specifically for simple, robust, and self-contained fan control in systems where reliability, minimal external components, and deterministic thermal response are critical.
FAQ
What is the exact factory-programmed temperature threshold for MAX6665ASA70?
The MAX6665ASA70 has a fixed, non-adjustable fan activation threshold of +70°C, programmed at wafer sort and verified per production test. This value is laser-trimmed and guaranteed across −40°C to +125°C ambient operation, with ±3°C maximum deviation. The MAX6665ASA70 does not support field adjustment or resistor-based threshold tuning.
How does the HYST pin configure hysteresis on the MAX6665ASA70?
On the MAX6665ASA70, the HYST pin selects hysteresis via three states: left unconnected = 1°C, tied to GND = 4°C, tied to VDD = 8°C. This sets the temperature deadband between fan turn-on and turn-off. For example, with HYST = VDD, the fan turns off when die temperature falls to +62°C after turning on at +70°C. Self-heating from fan current adds ~1.6–7.7°C effective hysteresis depending on load.
Can MAX6665ASA70 drive a 24V fan directly?
Yes, the MAX6665ASA70 can drive fans rated up to 24V, but only as a low-side switch: the fan's positive terminal connects to the 4.5–24V supply, and FANOUT connects to the fan's negative terminal. The MAX6665ASA70's FANOUT pin withstands up to +28V and delivers 250mA with ≤0.6V saturation voltage-enabling direct 24V fan control without level-shifting or external transistors.
What is the function of the WARN and OT outputs on MAX6665ASA70?
The WARN output on MAX6665ASA70 is an active-low open-drain signal asserted when die temperature reaches +85°C (+70°C +15°C), providing early thermal warning. The OT output is also active-low open-drain, asserted at +100°C (+70°C +30°C), indicating critical overtemperature requiring immediate system shutdown. Both require external pull-up resistors and interface directly with microcontrollers or power sequencers.
Does MAX6665ASA70 require external components for basic operation?
No, the MAX6665ASA70 operates autonomously with zero external components for core functionality: FANOUT drives the fan, FANON indicates state, and WARN/OT provide alarms. Only two recommended components improve robustness-1µF tantalum capacitor from VDD to GND (placed adjacent to Pin 7), and pull-up resistors on WARN and OT (typically 4.7kΩ to VDD)-to ensure clean logic-level signaling and noise immunity.
MAX6665ASA70 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Packaging:
- Bulk
- Product Status:
- Active
- Trip Temperature Threshold:
- Hot
- Switching Temperature:
- 70°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
MAX6665ASA70 FAQ
1.How can I place an order for MAX6665ASA70 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6665ASA70 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 MAX6665ASA70 reliable?
The price and inventory of MAX6665ASA70 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6665ASA70 is usually 5 days.
3.What payment methods are accepted for MAX6665ASA70?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6665ASA70 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6665ASA70?
MAX6665ASA70 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6665ASA70 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 MAX6665ASA70?
For technical support, including MAX6665ASA70 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6665ASA70 requirements.
6.How does Aetrix verify that MAX6665ASA70 is sourced from the original manufacturer or authorized distributors?
All MAX6665ASA70 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 MAX6665ASA70 meets industry standards.
7.What is the process for return or replacement of MAX6665ASA70?
All MAX6665ASA70 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6665ASA70, 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 MAX6665ASA70 part is unused and in its original packaging.
Return procedure for MAX6665ASA70:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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