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Analog Devices Inc./Maxim Integrated MAX5943EEEE+T
- Part No.:
- MAX5943EEEE+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- OR Controllers, Ideal Diodes
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
MAX5943EEEE+T.pdf
- Description:
- IC OR CTRLR N+1 16QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,222
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Product details
Overview
MAX5943EEEE+T from Maxim Integrated is a FireWire/IEEE 1394™ current-limiting and low-drop ORing switch controller that drives two external n-channel MOSFETs for hot-swap protection, inrush control, and bidirectional load disconnect. It operates from 7.5V to 37V input, provides ±5% current-limit sensing accuracy, supports programmable circuit-breaker timeout (4ms default), and is UL-recognized for FireWire applications.
For engineers reviewing the MAX5943EEEE+T datasheet, MAX5943EEEE+T pinout, MAX5943EEEE+T application, or MAX5943EEEE+T equivalent, this page delivers verified functional context, validated pin roles, confirmed FireWire-specific timing behavior, and real-world hot-swap design constraints - all grounded in the official MAX5943 family datasheet and selector guide.
Technical Context
The MAX5943EEEE+T implements dual-MOSFET control: GATE2 manages active current limiting or circuit-breaking (depending on variant) via fast pulldown currents up to 1.0A peak, while GATE1 enables ultra-low-drop ORing with turn-on threshold as low as 5mV and sub-100ns turn-off response. Its fault management supports latched or autoretry modes via the LATCH pin.
It integrates programmable thresholds (ILIM, OR_ADJ), adjustable timeouts (TIM), and ON-input–based undervoltage lockout with 6.5V nominal trip and 0.35V hysteresis. All logic inputs tolerate up to IN + 0.3V, and shutdown current is ≤10µA at VON ≤ 0.4V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 7.5V to 37V - supports full FireWire port power range without external regulation |
| Current-Limit Threshold Accuracy | ±5% - ensures precise overcurrent protection across temperature (-40°C to +85°C) |
| Circuit-Breaker Timeout (Default) | 4ms - fixed for MAX5943E variant; prevents sustained fault stress on MOSFETs and sense resistor |
| ORing Turn-On Threshold | 5mV to 12.8mV - selectable via OR_ADJ pin; enables <100mV total forward drop with typical RDS(ON) |
| Shutdown Supply Current | ≤10µA - allows safe system-level power gating without leakage concerns |
| GATE2 Peak Pulldown Current | 1.0A - ensures rapid MOSFET turn-off during short-circuit events (tON_OFF ≤ 0.6µs) |
| UL Recognition | UL® recognized FireWire/IEEE 1394 protective circuit - satisfies safety compliance for end-equipment certification |
Pinout & Package
MAX5943EEEE+T is housed in a 16-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch), optimized for space-constrained FireWire peripheral and hub designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (ON) | Enable / UVLO control input | Resets fault latch and sets undervoltage lockout threshold; connects to IN for default 6.5V trip |
| 2 (FAULT) | Active-low open-drain fault indicator | Asserts low after circuit-breaker timeout; requires external pullup for host MCU monitoring |
| 3 (TIM) | Timeout adjustment input | Connects to GND via RTIM resistor to scale default 4ms timeout (MAX5943E); floating = max timeout |
| 4 (ILIM) | Current-threshold selection input | Configures VTH = 50mV (GND), 60mV (IN), or 40mV (floating) - sets ILIMIT = VTH/RSENSE |
| 5 (LATCH) | Fault management mode select | GND = autoretry; IN = latched shutdown until ON toggled - critical for fail-safe FireWire hot-plug |
| 6 (OR_ADJ) | ORing threshold adjustment | Selects VOR = 5mV (GND), 7.5mV (floating), or 10.5mV (IN) - determines MOSFET turn-on point |
| 8 (ONQ1) | Manual ORing enable | Drives low for automatic ORing; high forces Q1 on regardless of current - used for reverse-current override |
| 9 (GND) | Analog/digital ground reference | Common return for sense, gate drive, and logic; must be low-impedance path to minimize noise coupling |
| 11 (OUT) | Output voltage sense node | Connects directly to load side of output capacitor; referenced by GATE2 charge pump and FAULT logic |
| 12 (GATE2) | Current-limit/circuit-breaker MOSFET gate driver | Charge-pump output driving Q2 gate; delivers 1.0A peak pulldown for fast load disconnect |
| 14 (GATE1) | ORing MOSFET gate driver | Charge-pump output driving Q1 gate; turns off in <100ns when OUT > IN to block backfeed |
| 15 (SENSE) | Current-sense negative input | Connects to low-side of RSENSE; differential voltage (VIN – SENSE) determines current-limit and ORing states |
| 16 (IN) | Input power and current-sense positive input | Primary power rail connection; also serves as reference for ON UVLO and ILIM/ORB_ADJ logic levels |
Key Features
| Feature | Design Value |
|---|---|
| UL-recognized FireWire protection | Meets safety requirements for IEEE 1394 port implementations without additional certification burden |
| Programmable circuit-breaker timeout | 4ms default (MAX5943E), scalable via TIM resistor - balances fault clearance speed vs. inrush tolerance |
| Low-drop ORing with ultra-fast turn-off | Sub-100ns GATE1 disable time prevents reverse current flow when OUT > IN - essential for multi-source FireWire hubs |
| ±5% current-limit sensing accuracy | Ensures consistent trip points across -40°C to +85°C, eliminating need for derating in industrial FireWire peripherals |
| Latched or autoretry fault management | Configurable via LATCH pin - supports fail-safe shutdown (latch) or self-recovery (autoretry) per system architecture |
| 10µA shutdown current | Enables true zero-power state during port idle or cable removal - critical for notebook FireWire power budgeting |
Applications
| FireWire Desktop/Notebook Port | FireWire Peripheral Device Current Limit |
|---|---|
|
Use Scenario: Hot-plugging FireWire audio interfaces or storage devices into live laptop ports. IC Role / Device Role / Timing Role: MAX5943EEEE+T acts as the primary current-limiting and ORing controller between the host port and peripheral load. Use Value: Prevents bus voltage collapse and protects host port from inrush surges up to 220µF load capacitance while enabling safe insertion/removal. |
Use Scenario: Protecting FireWire-powered external hard drives from overcurrent due to motor startup or shorted PCB traces. IC Role / Device Role / Timing Role: MAX5943EEEE+T monitors load current via RSENSE and disables Q2 within 4ms if threshold exceeded. Use Value: Limits fault energy to <100mJ (at 37V, 4ms), preventing thermal damage to USB/FireWire connector pins and internal traces. |
| FireWire Hub | Hot Swap |
|
Use Scenario: Multi-port FireWire hubs connecting mixed-voltage peripherals (e.g., battery-powered camcorders and AC-powered docks). IC Role / Device Role / Timing Role: MAX5943EEEE+T performs bidirectional ORing across upstream/downstream paths using GATE1 and independent sense paths. Use Value: Enables seamless power switchover between sources with <1V reverse isolation and <10µs response to voltage transients. |
Use Scenario: Industrial FireWire I/O modules requiring live replacement in powered-backplane systems. IC Role / Device Role / Timing Role: MAX5943EEEE+T provides controlled inrush limiting and true bidirectional disconnect via simultaneous GATE1/GATE2 shutdown. Use Value: Eliminates arcing at connectors and avoids brownouts in shared 12V/24V backplanes during module insertion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FireWire current-limiting and ORing applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX5943DEEE | 2ms default circuit-breaker timeout (vs. 4ms); identical pinout, package, and feature set | Better suited for lower-energy faults where faster disconnect is required (e.g., short cables, low-capacitance peripherals) | Select MAX5943DEEE if system-level fault energy budget requires shorter tCB; verify RSENSE power rating at reduced timeout |
| MAX5943CEEE | 1ms default circuit-breaker timeout; same ILIM/ORT_ADJ programming and GATE drive specs | Optimized for compact FireWire accessories with minimal output capacitance and tight thermal constraints | Choose MAX5943CEEE for space-limited designs needing faster fault response than MAX5943E but less aggressive than MAX5943D |
Compared with MAX5943DEEE and MAX5943CEEE, the MAX5943EEEE+T offers the longest standard circuit-breaker timeout (4ms), allowing higher transient inrush tolerance and relaxed RSENSE power dissipation - making it optimal for high-capacitance FireWire peripherals like docking stations and RAID enclosures.
Availability
MAX5943EEEE+T is available at Aetrix Electronics and suitable for FireWire desktop ports, FireWire peripheral current limiting, and FireWire hub designs requiring stable component supply, long-term lifecycle support, and UL-recognized safety compliance.
Supply support for MAX5943EEEE+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 computing applications.
The MAX5943 product line was designed specifically for IEEE 1394/FireWire power interface protection - delivering integrated hot-swap control, ORing, and programmable circuit-breaking in a single 16-pin QSOP device.
FAQ
What is the default circuit-breaker timeout for MAX5943EEEE+T?
The MAX5943EEEE+T has a default circuit-breaker timeout of 4ms when the TIM pin is connected to IN. This value is fixed for the MAX5943E variant and scales with an external RTIM resistor (4kΩ to 50kΩ) when TIM is pulled to GND. The 4ms timeout balances reliable inrush handling against fault energy limitation in FireWire peripheral applications.
How does MAX5943EEEE+T differ from MAX5943AEEE in current-limit functionality?
The MAX5943EEEE+T implements circuit-breaker operation (not active current limiting): it fully enhances Q2 during overcurrent and only disconnects after the 4ms timeout expires. In contrast, MAX5943AEEE actively regulates GATE2 to hold load current at the programmed ILIMIT level until timeout. This makes MAX5943EEEE+T unsuitable for constant-current applications but more robust for high-surge FireWire loads.
Can MAX5943EEEE+T be used in non-FireWire 12V systems?
Yes - MAX5943EEEE+T operates from 7.5V to 37V and functions as a general-purpose hot-swap and ORing controller. Its UL recognition applies specifically to FireWire, but the electrical behavior (current limiting, ORing, shutdown) remains valid in 12V industrial or telecom systems. Designers must validate layout, RSENSE rating, and MOSFET SOA independently of FireWire compliance.
What is the role of the ONQ1 pin on MAX5943EEEE+T?
The ONQ1 pin on MAX5943EEEE+T manually overrides the automatic ORing function: driving ONQ1 low enables normal ORing (GATE1 controlled by load current), while driving ONQ1 high forces GATE1 fully on - permitting reverse current flow from OUT to IN. This is used for battery backup scenarios or diagnostic modes where bidirectional conduction is required.
Does MAX5943EEEE+T support latched fault shutdown?
Yes - MAX5943EEEE+T supports latched fault shutdown when the LATCH pin is connected to IN. In this mode, after a circuit-breaker timeout, FAULT asserts low and remains latched until the ON pin is cycled (driven low then high). This behavior ensures persistent fault indication for host firmware and prevents automatic recovery in safety-critical FireWire applications.
MAX5943EEEE+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- N+1 ORing Controller
- FET Type:
- N-Channel
- Ratio - Input:Output:
- N:1
- Internal Switch(s):
- No
- Delay Time - ON:
- -
- Delay Time - OFF:
- 100 ns
- Current - Output (Max):
- -
- Current - Supply:
- 1.3 mA
- Voltage - Supply:
- 7.5V ~ 37V
- Applications:
- FireWire®
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QSOP
MAX5943EEEE+T FAQ
1.How can I place an order for MAX5943EEEE+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX5943EEEE+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 MAX5943EEEE+T reliable?
The price and inventory of MAX5943EEEE+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX5943EEEE+T is usually 5 days.
3.What payment methods are accepted for MAX5943EEEE+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX5943EEEE+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX5943EEEE+T?
MAX5943EEEE+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX5943EEEE+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 MAX5943EEEE+T?
For technical support, including MAX5943EEEE+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX5943EEEE+T requirements.
6.How does Aetrix verify that MAX5943EEEE+T is sourced from the original manufacturer or authorized distributors?
All MAX5943EEEE+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 MAX5943EEEE+T meets industry standards.
7.What is the process for return or replacement of MAX5943EEEE+T?
All MAX5943EEEE+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX5943EEEE+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 MAX5943EEEE+T part is unused and in its original packaging.
Return procedure for MAX5943EEEE+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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