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Analog Devices Inc./Maxim Integrated MAX4944ELA+T
- Part No.:
- MAX4944ELA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Power Management - Specialized
- Package:
- 8-WFDFN
- Datasheet:
-
MAX4944ELA+T.pdf
- Description:
- IC OVERVOLTAGE PROT CTRL 8UDFN
- Quantity:
- Payment:
- Shipping:
Inventory:32,500
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Product details
Overview
The MAX4944ELA+T from Maxim Integrated is an overvoltage-protection controller with integrated nFET switch, designed for input-side protection in portable power systems. It features a 6.35V (typ) overvoltage lockout (OVLO), 4.15V (typ) undervoltage lockout (UVLO), 80mΩ (typ) RON, 1.2A (min) current-limit protection, and autoretry fault recovery - used to safeguard USB-powered devices, battery chargers, and DC-DC input stages against +28V faults.
For engineers reviewing the MAX4944ELA+T datasheet, MAX4944ELA+T pinout, MAX4944ELA+T application, or MAX4944ELA+T equivalent, key selection criteria include its fixed 6.35V OVLO threshold, µDFN-8 package compatibility, autoretry behavior under short-circuit, ACOK power-good signaling, and thermal shutdown at +175°C.
Technical Context
The MAX4944ELA+T integrates a charge-pump–driven nFET switch with internal timing control: a 15ms (typ) debounce timer prevents false turn-on during adapter insertion, and a 30ms (typ) blanking period ensures stable ACOK assertion only after valid VIN settles between UVLO and OVLO thresholds.
Its protection logic combines dual-voltage monitoring (UVLO/VOVLO), fast 10µs (typ) overcurrent turn-off, open-drain ACOK output with pullup requirement, and GP pin capable of driving an external pFET for reverse-polarity protection down to –28V - all operating across –40°C to +85°C without external components beyond IN bypass capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| OVLO Threshold | 6.35V (typ); triggers immediate internal FET turn-off if input exceeds this level, preventing downstream damage from overvoltage events up to +28V. |
| UVLO Threshold | 4.15V (typ); disables switch and places device in low-current standby when input drops below this level, conserving system power. |
| RON | 80mΩ (typ) at 1A; minimizes conduction loss and voltage drop across the internal nFET switch in normal operation. |
| Current Limit | 1.2A (min); clamps output current during overload or short-circuit, limiting power dissipation and enabling safe autoretry cycling. |
| ACOK Assertion Time | 30ms (typ); delays ACOK low assertion until VIN remains within valid window for this duration, ensuring reliable power-good indication. |
| Thermal Shutdown | +175°C (typ); disables switch and enters fault mode if junction temperature exceeds this limit, with 40°C hysteresis for automatic recovery. |
| Package | 8-pin µDFN (2mm × 2mm); enables compact layout in space-constrained portable electronics with exposed pad for thermal performance. |
Pinout & Package
MAX4944ELA+T uses an 8-pin µDFN (2mm × 2mm) package with exposed thermal pad (L822-1). Pin 1 is marked by top-side dot; pins are numbered counterclockwise from top-left corner in top view.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 - IN | Voltage Input | Powers internal charge pump; requires 1µF ceramic bypass to GND for ±15kV HBM ESD protection and noise immunity. |
| 3 - GP | pFET Gate-Drive Output | Active-low open-drain output that pulls external pFET gate low when IN > 0V, enabling reverse-polarity protection down to –28V. |
| 4 - ACOK | Adapter-Voltage Indicator | Active-low open-drain logic output asserted low only after VIN remains within UVLO–OVLO window for 30ms (typ); requires external pullup. |
| 5 - GND | Ground Reference | Primary ground return for internal circuitry and charge pump; must be connected to system ground with low-impedance path. |
| 6, 7, 8 - OUT | Switch Output | Power output node of internal nFET; all three pins must be shorted together on PCB for rated current handling and thermal performance. |
Key Features
| Feature | Design Value |
|---|---|
| Autoretry Fault Recovery | 15ms (typ) retry interval after overcurrent fault - enables self-clearing short-circuit protection without manual reset or host intervention. |
| Integrated Charge Pump | Generates gate drive ≥5V above VIN to fully enhance internal nFET, eliminating need for external high-side driver or bootstrap circuitry. |
| Power-Good Signaling | ACOK output provides deterministic, debounced confirmation of stable adapter presence - simplifies microcontroller power sequencing logic. |
| Reverse Polarity Support | GP pin drives external pFET to block negative input voltages down to –28V, extending protection beyond internal FET capability. |
| Robust ESD Protection | ±15kV HBM (IN pin) and ±8kV IEC 61000-4-2 contact discharge - reduces need for external TVS diodes in consumer-grade portable designs. |
Applications
| USB-Powered Portable Devices | Smartphone Charging Circuits |
|---|---|
|
Use Scenario: Protecting USB input stage of Bluetooth headsets or portable speakers from faulty wall adapters or hot-plug transients. IC Role / Device Role / Timing Role: Input-side overvoltage protector with autoretry; monitors VIN and disables internal FET within 20µs if OVLO exceeded. Use Value: Prevents latch-up or permanent damage to downstream LDOs and PMICs during +28V adapter faults while maintaining plug-and-play usability. |
Use Scenario: Securing charging path in smartphones where USB input may be exposed to unregulated third-party chargers. IC Role / Device Role / Timing Role: Primary overvoltage guard before battery charger IC; asserts ACOK only after 30ms stable input window. Use Value: Eliminates false power-good assertions during adapter insertion bounce, reducing boot failures and improving user experience. |
| PDAs and Palmtop Devices | MP3 Player Power Inputs |
|
Use Scenario: Safeguarding legacy PDA mainboard inputs against accidental connection to industrial 12V supplies. IC Role / Device Role / Timing Role: Standalone OVLO/UVLO supervisor with integrated switch; operates independently of host processor. Use Value: Enables "set-and-forget" protection with no firmware dependency, critical for devices lacking real-time OS supervision. |
Use Scenario: Protecting audio codec and flash memory power rails in MP3 players powered via mini-USB. IC Role / Device Role / Timing Role: Low-RON pass element with thermal shutdown; limits peak power dissipation during sustained 1.2A load. Use Value: Maintains <100mV dropout at full rated current, preserving battery runtime while preventing thermal runaway in sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar overvoltage-protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX4944BELA+T | Latchoff (not autoretry) overcurrent response; same OVLO/UVLO thresholds and package. | Used where persistent fault isolation is required (e.g., medical diagnostics equipment), not self-recovering systems. | Select MAX4944BELA+T only if system-level safety mandates manual reset after overcurrent event. |
| TPD3S014RTER | Lower OVLO (5.7V max), no ACOK output, includes integrated USB data-line ESD protection (±15kV), 1.5A current limit. | Targeted at USB 2.0 data + power protection; lacks GP pin for reverse polarity support. | Choose TPD3S014RTER when USB data line protection is mandatory and reverse-polarity blocking is unnecessary. |
Compared with MAX4944ELA+T, MAX4944BELA+T removes autoretry for fail-safe latching, while TPD3S014RTER trades ACOK signaling and GP-driven reverse protection for integrated data-line ESD - making MAX4944ELA+T optimal for standalone, high-reliability power-input guarding with autonomous recovery.
Availability
MAX4944ELA+T is available at Aetrix Electronics and suitable for USB-powered portable devices, smartphone charging circuits, and MP3 player power inputs requiring stable component supply, RoHS-compliant packaging, and tape-and-reel delivery for automated assembly.
Supply support for MAX4944ELA+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.
The MAX4943–MAX4946/MAX4949 family was designed specifically for robust, single-chip overvoltage and reverse-polarity protection in battery-powered portable electronics - prioritizing low RON, precise voltage thresholds, and autonomous fault recovery without host processor involvement.
FAQ
What is the overvoltage lockout (OVLO) threshold for MAX4944ELA+T?
The MAX4944ELA+T has a preset overvoltage lockout threshold of 6.35V (typical), with a guaranteed range of 6.00V to 6.70V across temperature. This value is factory-trimmed and nonadjustable. When the input voltage exceeds this threshold, the internal nFET switch turns off within 20µs to protect downstream circuitry from faults up to +28V. The MAX4944ELA+T does not support external OVLO adjustment.
Does MAX4944ELA+T support reverse-polarity protection?
The MAX4944ELA+T itself does not provide reverse-polarity protection directly, but it enables it via its GP (gate-drive) pin. When IN rises above ground, GP pulls low to turn on an external p-channel MOSFET placed between the input source and the protected load. This configuration blocks reverse current and protects down to –28V, provided the external pFET's VGS rating and breakdown voltage are appropriately selected. The MAX4944ELA+T datasheet includes recommended pFET selection guidelines.
How does the ACOK output behave during startup and fault conditions?
The ACOK output of MAX4944ELA+T is an active-low open-drain signal that remains high-impedance until VIN stabilizes between the UVLO (4.15V) and OVLO (6.35V) thresholds for 30ms (typical). Once asserted low, ACOK stays low as long as VIN remains in that window. If VIN drops below UVLO or rises above OVLO, ACOK immediately goes high-impedance. During overcurrent or thermal faults, ACOK deasserts due to VIN instability or internal disable - confirming loss of valid input condition.
What is the difference between MAX4944ELA+T and MAX4944BELA+T?
The MAX4944ELA+T implements autoretry overcurrent protection - turning off for 15ms (typ) then automatically attempting reconnection. In contrast, MAX4944BELA+T uses latchoff behavior: once tripped by overcurrent, it remains off until VIN cycles below UVLO and back into the valid window. Both share identical OVLO (6.35V), UVLO (4.15V), RON, and package. The choice depends on system safety requirements: autoretry suits consumer devices needing resilience; latchoff suits safety-critical applications requiring explicit reset.
What external components are required for basic operation of MAX4944ELA+T?
For basic operation, MAX4944ELA+T requires only a 1µF ceramic capacitor from IN to GND (placed as close as possible to the device) to enable ±15kV HBM ESD protection and stabilize the charge pump. An external pullup resistor (typically 10kΩ) from ACOK to the host logic rail is needed for proper power-good signaling. No resistors, capacitors, or feedback networks are required for OVLO/UVLO thresholds - they are internally preset and factory-trimmed. The GP pin may drive an external pFET if reverse-polarity protection is desired.
MAX4944ELA+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-WFDFN
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Applications:
- Overvoltage Protection Controller
- Current - Supply:
- 50µA
- Voltage - Supply:
- 2.2V ~ 28V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-µDFN (2x2)
MAX4944ELA+T FAQ
1.How can I place an order for MAX4944ELA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX4944ELA+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 MAX4944ELA+T reliable?
The price and inventory of MAX4944ELA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX4944ELA+T is usually 5 days.
3.What payment methods are accepted for MAX4944ELA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX4944ELA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX4944ELA+T?
MAX4944ELA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX4944ELA+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 MAX4944ELA+T?
For technical support, including MAX4944ELA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX4944ELA+T requirements.
6.How does Aetrix verify that MAX4944ELA+T is sourced from the original manufacturer or authorized distributors?
All MAX4944ELA+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 MAX4944ELA+T meets industry standards.
7.What is the process for return or replacement of MAX4944ELA+T?
All MAX4944ELA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX4944ELA+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 MAX4944ELA+T part is unused and in its original packaging.
Return procedure for MAX4944ELA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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