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Analog Devices Inc./Maxim Integrated MAX4944LELA+
- Part No.:
- MAX4944LELA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Power Management - Specialized
- Package:
- 8-WFDFN
- Datasheet:
-
MAX4944LELA+.pdf
- Description:
- IC OVERVOLTAGE PROT CTRL 8UDFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,775
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Product details
Overview
The MAX4944LELA+ from Maxim Integrated is an overvoltage-protection controller with integrated nFET switch, designed for input-side protection in portable low-voltage systems. It features a 6.35V (typ) overvoltage lockout (OVLO), 2.45V (typ) undervoltage lockout (UVLO), 80mΩ (typ) RON, 1.2A (min) current-limit protection, and autoretry fault recovery - used in USB-powered devices to safeguard downstream DC-DC converters and microcontrollers from adapter overvoltage events.
For engineers reviewing the MAX4944LELA+ datasheet, MAX4944LELA+ pinout, MAX4944LELA+ application, or MAX4944LELA+ equivalent, key selection considerations include its 2.45V UVLO threshold (lower than standard 4.15V variants), µDFN-8 (2mm × 2mm) package, 15ms autoretry timing, ACOK power-good signaling, and compatibility with external pFET reverse-polarity protection down to –28V.
Technical Context
The MAX4944LELA+ integrates a charge-pump–driven n-channel MOSFET switch with precision voltage comparators for OVLO and UVLO monitoring. Its internal oscillator enables a 15ms (typ) debounce timer before turn-on and a 30ms (typ) ACOK assertion delay after valid input stabilization.
It implements fast fault response: switch turn-off occurs within 2µs during overvoltage/undervoltage events and within 10µs during overcurrent faults. The GP pin drives an external pFET gate with clamped voltage (≤19V differential vs. IN) and includes thermal shutdown at +175°C (typ) with 40°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| OVLO Threshold | 6.35V (typ); triggers immediate switch turn-off if input exceeds this level, protecting downstream 3.3V/5V circuitry. |
| UVLO Threshold | 2.45V (typ); disables switch and places device in low-current standby below this rail, enabling battery-backed operation. |
| RON | 80mΩ (typ) at 1A; minimizes forward voltage drop and power loss in high-current adapter paths. |
| Current Limit | 1.2A (min); limits fault current to prevent trace damage and thermal runaway during short circuits. |
| Autoretry Time | 15ms (typ); enables automatic recovery after transient overloads without host intervention. |
| ACOK Assertion Delay | 30ms (typ); provides stable power-good signal only after sustained valid input, avoiding false system wake-up. |
| Operating Temp | –40°C to +85°C; qualified for industrial and portable consumer environments including handheld electronics. |
Pinout & Package
Package: 8-pin µDFN (2mm × 2mm), exposed pad, RoHS-compliant, top-mark ABD.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 - IN | Input voltage supply and charge-pump source | Powers internal circuitry and charge pump; requires 1µF ceramic bypass for ±15kV HBM ESD protection. |
| 3 - GP | External pFET gate-drive output | Pulls external p-channel FET gate low when IN > GND; clamped to ≤19V differential vs. IN for safe pFET biasing. |
| 4 - ACOK | Active-low open-drain power-good indicator | Asserts low only after VIN remains between 2.45V and 6.35V for ≥30ms; requires external pullup to host I/O voltage. |
| 5 - GND | Ground reference | Common return for all internal circuitry and external bypass capacitors; must be low-impedance connection. |
| 6, 7, 8 - OUT | Switch output node | Delivers protected output voltage; pins must be shorted together to handle full rated current and minimize inductance. |
Key Features
| Feature | Design Value |
|---|---|
| Low RON nFET switch | 80mΩ (typ) reduces conduction loss and self-heating in 1A adapter paths, improving efficiency and thermal margin. |
| Configurable UVLO | 2.45V (typ) threshold enables operation with partially discharged batteries or low-voltage adapters not supported by 4.15V variants. |
| Autoretry fault management | 15ms retry cycle automatically restores power after transient overloads, eliminating need for manual reset or host firmware intervention. |
| ACOK power-good signaling | 30ms blanking period ensures reliable system power sequencing and prevents premature microcontroller wake-up during input ramp-up. |
| Reverse polarity support | GP pin drives external pFET to block –28V faults, extending protection beyond internal switch capability without additional control logic. |
Applications
| USB-Powered Portable Devices | Digital Still Cameras |
|---|---|
Use Scenario: USB wall adapter supplies power to camera mainboard with sensitive image sensor and processor rails. IC Role / Device Role / Timing Role: Input-side overvoltage protector that isolates downstream 3.3V/1.8V regulators from adapter transients. Use Value: Prevents latch-up or permanent damage to CMOS image sensors during 12V adapter misconnection, using 6.35V OVLO and fast 2µs turn-off. |
Use Scenario: Compact digital camera uses Li-ion battery and optional AC adapter; requires robust input fault handling during hot-swap events. IC Role / Device Role / Timing Role: Primary input supervisor with UVLO/UVLO hysteresis and ACOK sequencing for system power manager. Use Value: 2.45V UVLO allows continued operation during battery sag; ACOK enables precise power-on reset timing for flash memory initialization. |
| MP3 Players | PDAs and Palmtop Devices |
Use Scenario: MP3 player accepts both 5V USB and higher-voltage proprietary adapters; must tolerate accidental 9V/12V input. IC Role / Device Role / Timing Role: Overvoltage guard with autoretry behavior to survive repeated plug/unplug cycles without user reset. Use Value: 15ms autoretry restores audio playback automatically after brief short-circuit events (e.g., headphone jack debris), improving user experience. |
Use Scenario: PDA with dual-power sources (battery + AC adapter) requires seamless transition and reverse-polarity immunity. IC Role / Device Role / Timing Role: Dual-role protector: internal switch handles +28V overvoltage, GP pin controls external pFET for –28V reverse blocking. Use Value: Enables single-chip solution for bidirectional fault protection, reducing BOM count versus discrete diode/FET approaches. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar overvoltage-protection controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX4944ELA+T | UVLO = 4.15V (typ); same OVLO = 6.35V, same autoretry mode, identical pinout and package. | Not suitable for sub-4V battery-backed operation; intended for stable 5V adapter-only use cases. | Select MAX4944ELA+T when system never operates below 4.15V and higher UVLO improves noise immunity. |
| MAX4945LELA+T | OVLO = 5.80V (typ); UVLO = 2.45V (typ); same autoretry, same package and pinout. | Better suited for 5V-tolerant systems requiring tighter overvoltage margin (e.g., legacy USB peripherals). | Choose MAX4945LELA+T where 5.80V OVLO provides improved safety margin against 5.5V rail excursions. |
Compared with MAX4944LELA+, MAX4944ELA+T raises UVLO by 1.7V - limiting low-voltage battery operation but improving noise rejection - while MAX4945LELA+ lowers OVLO by 0.55V to tighten overvoltage guardband for 5V-centric designs, retaining identical footprint and fault-handling behavior.
Availability
MAX4944LELA+ is available at Aetrix Electronics and suitable for USB-powered portable devices, digital still cameras, MP3 players, PDAs, and palmtop devices requiring stable component supply across industrial temperature ranges and long production lifecycles.
Supply support for MAX4944LELA+ 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 input protection in space-constrained portable electronics, integrating precision voltage supervision, low-loss switching, and fault resilience in miniature µDFN packages.
FAQ
What is the overvoltage lockout (OVLO) threshold for MAX4944LELA+?
The MAX4944LELA+ has a preset overvoltage lockout threshold of 6.35V (typical), with ±0.35V tolerance over temperature. This value is factory-trimmed and fixed - no external resistor configuration is required. When the input voltage exceeds 6.35V, the internal nFET switch turns off within 2µs to protect downstream circuitry. The MAX4944LELA+ shares this OVLO setting with other MAX4944_ variants but differs in UVLO level.
Does MAX4944LELA+ support reverse polarity protection?
Yes, the MAX4944LELA+ supports reverse polarity protection via its GP pin, which drives the gate of an external p-channel MOSFET. When the input voltage drops below ground, GP pulls low to turn off the pFET, blocking reverse current down to –28V (with appropriate pFET selection). This function is independent of the internal nFET and requires no additional control signals - the GP pin's clamped voltage (≤19V differential vs. IN) ensures safe pFET gate biasing.
What is the purpose of the ACOK pin on MAX4944LELA+?
The ACOK pin on MAX4944LELA+ is an active-low, open-drain output that signals valid input voltage presence. It asserts low only after the input voltage remains stably between 2.45V and 6.35V for 30ms (typical), providing a clean power-good signal for system sequencing. A pullup resistor to the host's logic I/O voltage is required. During overvoltage, undervoltage, or overcurrent faults, ACOK goes high-impedance or deasserts, enabling fail-safe system response.
How does the autoretry functionality work in MAX4944LELA+?
In MAX4944LELA+, autoretry initiates after an overcurrent fault: the internal switch turns off, waits 15ms (typical), then attempts to re-enable. If the fault persists, it repeats the cycle; if cleared, the switch remains on. This behavior avoids latching off permanently during transient shorts (e.g., connector arcing or ESD-induced momentary overload). Unlike latchoff variants (e.g., MAX4944BELA+T), MAX4944LELA+ requires no manual reset or power cycle to recover.
What package type and footprint does MAX4944LELA+ use?
The MAX4944LELA+ uses an 8-pin µDFN package measuring 2mm × 2mm with an exposed thermal pad, marked "ABD" on top. Its land pattern matches the L822-1 package code per Maxim's document 21-0164. All eight pins are surface-mount; pins 6–8 (OUT) must be shorted externally to carry full rated current and minimize parasitic inductance. The package supports reflow soldering and is RoHS-compliant.
MAX4944LELA+ 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)
MAX4944LELA+ FAQ
1.How can I place an order for MAX4944LELA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX4944LELA+ 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 MAX4944LELA+ reliable?
The price and inventory of MAX4944LELA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX4944LELA+ is usually 5 days.
3.What payment methods are accepted for MAX4944LELA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX4944LELA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX4944LELA+?
MAX4944LELA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX4944LELA+ 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 MAX4944LELA+?
For technical support, including MAX4944LELA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX4944LELA+ requirements.
6.How does Aetrix verify that MAX4944LELA+ is sourced from the original manufacturer or authorized distributors?
All MAX4944LELA+ 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 MAX4944LELA+ meets industry standards.
7.What is the process for return or replacement of MAX4944LELA+?
All MAX4944LELA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX4944LELA+, 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 MAX4944LELA+ part is unused and in its original packaging.
Return procedure for MAX4944LELA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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