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Melexis Technologies NV US91AEZE-AAA-000-SP
- Part No.:
- US91AEZE-AAA-000-SP
- Manufacturer:
- Melexis Technologies NV
- Category:
- Motor Drivers, Controllers
- Package:
- SOT-23-5 Flat Leads
- Datasheet:
-
US91AEZE-AAA-000-SP.pdf
- Description:
- IC MOTOR DRIVER 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,206
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Product details
Overview
US91AEZE-AAA-000-SP from Melexis is a Hall-effect-based two-coil brushless DC fan driver IC with integrated rotation detection (RD) output, no-VDD architecture, 500 mA peak output current, and SOT25 straight-leads package. It drives 12V/24V cooling fans while providing alarm signaling upon rotor stall.
For engineers reviewing the US91AEZE-AAA-000-SP datasheet, pinout, applications, or equivalent options, key selection criteria include RD alarm functionality, locked-rotor protection timing (210–350 ms ON), thermal resistance (170°C/W for ZE), and compatibility with 2-coil fan topologies requiring open-drain tach/alarms.
Technical Context
The US91AEZE-AAA-000-SP implements a Hall-effect sensor with dynamic offset correction and dual low-side MOSFET drivers in a single die. Its no-VDD design eliminates the need for a dedicated supply pin by deriving power from the fan coil path, enabling compact 4-pin packaging.
It delivers RD (rotation detection) as an active-low open-drain signal that transitions high during stalled conditions (<60 RPM), with built-in LRP auto-restart cycling every 1.5 seconds. Output clamping (60–80 V) and integrated protection diodes eliminate external transient suppression components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Fan Supply Voltage | 4.7 V to 30 V - supports 12 V and 24 V DC fans; minimum VDD depends on coil resistance and IDD |
| Peak Output Current | 500 mA - limits inrush current at startup; defined by RCOIL and RDSON without external limiting |
| Continuous Output Current | 250 mA - sustainable coil drive level during normal rotation; determines thermal load under steady state |
| RD Output Clamp Voltage | 28 V - protects downstream monitoring ICs from overvoltage when RD is pulled up externally |
| Locked Rotor ON Time | 210–350 ms - defines duration of coil current cutoff before auto-restart; prevents thermal damage |
| Magnetic Operate Point | 3–6 mT - Hall sensor activation threshold; ensures reliable commutation across temperature and aging |
| Junction Temperature Range | −40 °C to +125 °C - validated operating range for industrial fan control in enclosed enclosures |
Pinout & Package
SOT25 package (straight leads), 5-pin outline with one NC terminal; thermally optimized for surface-mount assembly and airflow-constrained fan modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FG (RD) | Open-drain alarm output | Active-low RD signal; pulled high externally to monitor rotation status; high = stall detected |
| OUT1 | Low-side coil driver 1 | Switches first fan winding; driven low during North-pole detection per magnetic pole table |
| OUT2 | Low-side coil driver 2 | Switches second fan winding; complements OUT1; driven low during South-pole detection |
| GND | Power and signal reference | Common return for coil current, Hall sensor, and RD pull-up; must be low-impedance for EMC |
| N.C. | No connection | Unused pin; recommended to tie to GND for optimal EMC per datasheet guidance |
Key Features
| Feature | Design Value |
|---|---|
| No-VDD architecture | Eliminates dedicated supply pin and reverse-voltage protection diode; enables 4-pin TO92 and SOT25 packaging |
| Integrated RD alarm output | Provides immediate stall indication without external logic; reduces BOM count vs discrete Hall + comparator solutions |
| Locked rotor protection (LRP) | Auto-shutdown and 1.5-second restart cycle limits average stall current to 1/7 of normal, preventing fan burnout |
| Built-in output clamping diode | Clamps transients up to 80 V at OUT1/OUT2; removes need for external zener or TVS on coil paths |
| RoHS-compliant SOT25 package | Lead-free, straight-leads variant optimized for automated pick-and-place and reflow soldering in high-volume fan modules |
Applications
| Server Fan Control | Industrial PLC Cooling |
|---|---|
Use Scenario: 24 V, 2-coil blower fan in 1U server chassis with thermal throttling and fault reporting requirements. IC Role / Device Role / Timing Role: Fan driver with RD alarm output connected to BMC for real-time stall detection and system-level thermal event logging. Use Value: Enables automatic fan failure escalation without host CPU intervention; RD signal directly interfaces with Super I/O or hardware monitor ICs. |
Use Scenario: Enclosed programmable logic controller cabinet with ambient temperatures up to 70 °C and forced-air cooling. IC Role / Device Role / Timing Role: Brushless DC fan controller implementing LRP to prevent coil overheating during mechanical jam in dusty environments. Use Value: Prevents thermal runaway during obstruction events; 125 °C junction rating ensures reliability under sustained high-temperature operation. |
| Medical Diagnostic Equipment | Telecom Base Station Fans |
Use Scenario: Low-noise cooling fan in MRI-compatible diagnostic imaging unit requiring EMI-robust motor control. IC Role / Device Role / Timing Role: Hall-sensor-based commutator with integrated clamping and no-VDD design to minimize conducted emissions from coil switching. Use Value: Reduces external component count and PCB footprint; fan coils act as inherent ESD filters per datasheet application note. |
Use Scenario: High-reliability 12 V fan module in outdoor telecom base station with wide temperature cycling and vibration exposure. IC Role / Device Role / Timing Role: Two-coil fan driver with RD output wired to remote monitoring unit for predictive maintenance alerts. Use Value: RD alarm enables early detection of bearing wear or dust accumulation before complete failure; supports field-service SLA compliance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar brushless DC fan driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| US91AVK-AAA-000-BU | Same silicon, VK package (4-pin TO92); higher thermal resistance (200°C/W) and through-hole mounting | Used in legacy fan assemblies with manual soldering or wave-solder processes; lacks SMT compatibility | Select for cost-sensitive, low-volume, or repair-focused applications where SMT infrastructure is unavailable |
| US91ADC-AAA-000-RX | Same silicon, SOIC-8 package; includes four NC pins; lower thermal resistance (150°C/W); bent leads | Preferred for designs requiring higher power dissipation margin or compatibility with existing SOIC footprints | Select when board layout allows larger footprint and thermal performance exceeds ZE package capability |
Compared with US91AEZE-AAA-000-SP, the VK variant trades SMT scalability for simpler assembly, while the DC variant offers superior thermal management at the cost of PCB area-neither is pin-compatible, but all share identical RD functionality, LRP timing, and magnetic thresholds.
Availability
US91AEZE-AAA-000-SP is available at Aetrix Electronics and suitable for server fan control, industrial PLC cooling, and telecom base station fans requiring stable component supply, RoHS compliance, and long-lifecycle support.
Supply support for US91AEZE-AAA-000-SP 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
Melexis is a Belgian semiconductor company specializing in sensor and driver ICs for automotive, industrial, and consumer applications, with ISO/TS 16949 and ISO 14001 certification.
The US91A product line delivers integrated Hall-effect fan drivers targeting cost-sensitive, high-reliability cooling systems where space, thermal efficiency, and functional safety (stall detection) are critical.
FAQ
What is the primary function of the US91AEZE-AAA-000-SP in a cooling system?
The US91AEZE-AAA-000-SP functions as a two-coil brushless DC fan driver with integrated rotation detection (RD). It replaces discrete Hall sensors, drivers, and protection components by combining Hall sensing, low-side MOSFET drivers, and an open-drain RD alarm output in a single SOT25 package. The US91AEZE-AAA-000-SP directly controls fan commutation and signals stall events to system monitoring circuitry.
Does the US91AEZE-AAA-000-SP require an external VDD supply?
No, the US91AEZE-AAA-000-SP uses a patented no-VDD architecture: it derives operating power from the fan coil path instead of a dedicated supply pin. This eliminates the need for external VDD routing and reverse-voltage protection diodes, simplifying PCB layout and improving robustness. The US91AEZE-AAA-000-SP operates across 4.7 V to 30 V fan supply voltages.
How does the RD output of the US91AEZE-AAA-000-SP indicate fan stall?
The RD output of the US91AEZE-AAA-000-SP is an active-low open-drain signal that remains low during normal rotation and transitions high when rotational speed drops below 60 RPM (for a 4-pole magnet), indicating mechanical blockage. This behavior is intrinsic to the US91AEZE-AAA-000-SP's internal logic and requires only an external pull-up resistor to interface with monitoring ICs.
What thermal performance can be expected from the US91AEZE-AAA-000-SP in SOT25 package?
The US91AEZE-AAA-000-SP in ZE (SOT25) package has a junction-to-ambient thermal resistance (RTHja) of 170°C/W on a JEDEC standard board. Its junction-to-case (RTHjc) is 20°C/W, supporting direct thermal pad attachment. These values enable reliable operation at full 250 mA continuous current up to +125°C junction temperature, provided board layout meets datasheet copper guidelines.
Is the US91AEZE-AAA-000-SP pin-compatible with other US91A variants like US91AVK or US91ADC?
No, the US91AEZE-AAA-000-SP is not pin-compatible with US91AVK (VK TO92) or US91ADC (SOIC-8) variants. While all share identical electrical functionality and RD behavior, their pin counts and layouts differ: US91AEZE-AAA-000-SP uses 5-pin SOT25 with one NC pin, US91AVK uses 4-pin VK, and US91ADC uses 8-pin SOIC with four NC pins. PCB redesign is required for substitution.
US91AEZE-AAA-000-SP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Melexis Technologies NV
- Series:
- -
- Package/Case:
- SOT-23-5 Flat Leads
- Packaging:
- Bulk
- Product Status:
- Not For New Designs
- Motor Type - Stepper:
- -
- Motor Type - AC, DC:
- Brushless DC (BLDC)
- Function:
- Driver - Fully Integrated, Control and Power Stage
- Output Configuration:
- -
- Interface:
- On/Off
- Technology:
- -
- Step Resolution:
- -
- Applications:
- Fan Motor Driver
- Current - Output:
- 250mA
- Voltage - Supply:
- 4.7V ~ 30V
- Voltage - Load:
- 4.7V ~ 30V
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-25
US91AEZE-AAA-000-SP FAQ
1.How can I place an order for US91AEZE-AAA-000-SP through Aetrix?
Please submit a Request for Quotation (RFQ) for US91AEZE-AAA-000-SP 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 US91AEZE-AAA-000-SP reliable?
The price and inventory of US91AEZE-AAA-000-SP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for US91AEZE-AAA-000-SP is usually 5 days.
3.What payment methods are accepted for US91AEZE-AAA-000-SP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for US91AEZE-AAA-000-SP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for US91AEZE-AAA-000-SP?
US91AEZE-AAA-000-SP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your US91AEZE-AAA-000-SP 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 US91AEZE-AAA-000-SP?
For technical support, including US91AEZE-AAA-000-SP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your US91AEZE-AAA-000-SP requirements.
6.How does Aetrix verify that US91AEZE-AAA-000-SP is sourced from the original manufacturer or authorized distributors?
All US91AEZE-AAA-000-SP 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 US91AEZE-AAA-000-SP meets industry standards.
7.What is the process for return or replacement of US91AEZE-AAA-000-SP?
All US91AEZE-AAA-000-SP units undergo pre-shipment inspection (PSI). If there is an issue with US91AEZE-AAA-000-SP, 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 US91AEZE-AAA-000-SP part is unused and in its original packaging.
Return procedure for US91AEZE-AAA-000-SP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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