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Analog Devices Inc./Maxim Integrated MAX5943BEEE+
- Part No.:
- MAX5943BEEE+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- OR Controllers, Ideal Diodes
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
MAX5943BEEE+.pdf
- Description:
- IC OR CTRLR N+1 16QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,472
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Product details
Overview
MAX5943BEEE+ from Maxim Integrated is a FireWire/IEEE 1394™ protective power-management IC that controls two external n-channel MOSFETs to implement hot-swap current limiting and low-drop power-supply ORing. It operates from 7.5V to 37V input, provides ±5% current-limit sensing accuracy, programmable circuit-breaker timeout (5.5ms default), and true bidirectional load disconnect. It is UL-recognized and used in FireWire desktop/notebook ports and hubs.
For engineers reviewing the MAX5943BEEE+ datasheet, MAX5943BEEE+ pinout, MAX5943BEEE+ application, or MAX5943BEEE+ equivalent, key selection considerations include its 16-pin QSOP package, circuit-breaker (not active current-limit) behavior, 50mV default current-threshold setting (ILIM = GND), and compatibility with FireWire hot-plug safety requirements.
Technical Context
The MAX5943BEEE+ implements a non-regulating circuit-breaker function: during overcurrent, it keeps GATE2 fully enhanced until the programmed timeout expires, then asserts FAULT and pulls GATE2 low with 125mA pulldown current to disconnect the load. Its ORing control (GATE1) uses a programmable 5–12.8mV turn-on threshold (via OR_ADJ) and achieves ultra-fast turn-off (<100ns) for reverse-voltage protection.
It features latched or autoretry fault management (selected via LATCH pin), ON/OFF control with undervoltage lockout (6.5V typical UVLO), and shutdown current <10µA. All logic inputs tolerate up to IN + 0.3V, and GATE1/GATE2 drive voltages are internally regulated to ~5.5V above SENSE or OUT respectively.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 7.5V to 37V - supports full FireWire port supply range including legacy 12V and high-headroom 37V systems. |
| Circuit-Breaker Threshold | 50mV (ILIM = GND) - sets trip point at ITRIP = 50mV / RSENSE; ±5% accuracy ensures reliable overcurrent detection. |
| Default Timeout (TIM = IN) | 5.5ms - fixed circuit-breaker hold time before GATE2 shutdown; prevents nuisance tripping during transient surges. |
| GATE2 Pulldown Current | 125mA (typ) - ensures rapid MOSFET turn-off for fast load disconnect and fault isolation. |
| ORing Turn-On Threshold | 10.5mV (typ, OR_ADJ = IN) - enables low-loss power-path conduction with minimal forward voltage drop across Q1. |
| Shutdown Supply Current | <10µA - allows system-level power gating without significant standby drain. |
| Operating Temperature | −40°C to +85°C - qualified for industrial and computing environments including notebook thermal zones. |
Pinout & Package
MAX5943BEEE+ is housed in a 16-pin QSOP (Quarter-Size Outline Package) with 0.154" body width and 0.025" lead pitch, suitable for high-density FireWire port designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (ON) | Enable & UVLO control | Drives high to enable; connects to IN for 6.5V default UVLO; resistor divider enables custom threshold programming. |
| 2 (FAULT) | Active-low fault status | Open-drain output latches low after circuit-breaker timeout; signals host controller to initiate recovery or shutdown. |
| 3 (TIM) | Timeout adjustment | Connect to IN for 5.5ms default; RTIM to GND programs timeout per MAX5943B-specific scaling (K=32). |
| 4 (ILIM) | Current-threshold select | GND = 50mV threshold; floating = 40mV; IN = 60mV - selects trip level without external components. |
| 5 (LATCH) | Fault management mode | IN = latch-off after fault; GND = autoretry - determines whether manual reset or automatic recovery is required. |
| 6 (OR_ADJ) | ORing threshold select | GND = 5mV; floating = 7.5mV; IN = 10.5mV - configures turn-on sensitivity for optimal diode-replacement efficiency. |
| 8 (ONQ1) | Manual ORing override | Low = auto ORing; high = force Q1 on - enables controlled reverse-current paths or test modes. |
| 9 (GND) | Analog/digital reference | Single ground connection for all internal circuits and sense resistor return - critical for accurate current measurement. |
| 11 (OUT) | Output voltage sense | Connects to load-side of Q2 - enables accurate sensing of output voltage for ORing comparator and fault monitoring. |
| 12 (GATE2) | Current-limit MOSFET driver | Drives gate of Q2 (load-switch MOSFET); charge-pump output with 45µA pullup and 125mA pulldown for fast switching. |
| 14 (GATE1) | ORing MOSFET driver | Drives gate of Q1 (ORing MOSFET); regulated 5.5V above SENSE for low-RDS(ON) enhancement and fast turn-off. |
| 15 (SENSE) | Current-sense negative input | Connects to low side of RSENSE - forms Kelvin sense path with IN to reject common-mode noise and trace resistance errors. |
| 16 (IN) | Power input & sense positive | Connects to power source and high side of RSENSE - serves as both supply rail and current-sense reference node. |
Key Features
| Feature | Design Value |
|---|---|
| UL-recognized FireWire protection | Meets UL recognition requirements for IEEE 1394 safety-critical applications - eliminates need for separate certification effort. |
| Programmable circuit-breaker timeout | Configurable via TIM pin and RTIM resistor; MAX5943B-specific scaling (K=32) enables precise fault-hold timing from µs to ms range. |
| True bidirectional load disconnect | Simultaneous GATE1/GATE2 shutdown blocks current flow in both directions - prevents backfeed and enables safe hot removal. |
| Low-drop ORing with ultra-fast turn-off | Turn-off response <100ns ensures immediate blocking when reverse voltage appears at OUT - protects upstream supplies. |
| ±5% current-limit sensing accuracy | Guaranteed over −40°C to +85°C - enables robust overcurrent protection without derating or margin stacking. |
Applications
| FireWire Desktop Port Protection | FireWire Peripheral Current Limiting |
|---|---|
|
Use Scenario: Safely inserting/removing FireWire peripherals into live desktop PC ports without damaging host controller or cable. IC Role / Device Role / Timing Role: Acts as hot-swap controller and ORing switch; monitors IN–SENSE voltage to enforce current limit and detects reverse voltage at OUT to disable Q1 within 100ns. Use Value: Prevents bus lockup and component damage during hot-plug events; enables compliance with IEEE 1394 power management requirements. |
Use Scenario: Limiting inrush and steady-state current drawn by FireWire audio interfaces, storage devices, or video capture units. IC Role / Device Role / Timing Role: Controls external Q2 to interrupt load current after 5.5ms if sensed voltage exceeds 50mV; asserts FAULT to signal host MCU. Use Value: Protects peripheral's internal circuitry and host port from overcurrent faults while maintaining UL recognition. |
| FireWire Hub Power Management | Industrial Hot-Swap Module |
|
Use Scenario: Distributing power across multiple downstream FireWire ports in a hub, with independent current limiting per port. IC Role / Device Role / Timing Role: Provides per-port ORing (via GATE1) and circuit-breaker (via GATE2); LATCH pin configures autoretry for self-healing after transient overload. Use Value: Enables graceful degradation - single-port fault does not disable entire hub; reduces service downtime. |
Use Scenario: Hot-swapping power modules in industrial test equipment or modular instrumentation where FireWire-compatible voltage rails are used. IC Role / Device Role / Timing Role: Functions as a general-purpose 7.5–37V circuit-breaker with programmable trip threshold and timeout; GATE1 supports redundant supply ORing. Use Value: Replaces discrete fuse/MOSFET solutions with integrated, temperature-stable, and field-programmable protection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FireWire/IEEE 1394 circuit-breaker applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX5943CEEE+ | Default circuit-breaker timeout = 10ms (vs. 5.5ms); otherwise identical pinout, thresholds, and feature set. | Suitable for higher-energy fault conditions requiring longer hold time before disconnect - e.g., large-capacitance peripherals. | Select MAX5943CEEE+ when longer fault tolerance is needed; no PCB changes required. |
| MAX5943DEEE+ | Default circuit-breaker timeout = 20ms; same ILIM/ORTADJ/LATCH functionality and 16-QSOP package. | Better suited for systems with slow-rising inrush currents or legacy FireWire implementations with marginal voltage margins. | Choose MAX5943DEEE+ for applications where 5.5ms timeout causes false trips; verify thermal stress on Q2 during extended timeout. |
Compared with MAX5943BEEE+, MAX5943CEEE+ extends fault-hold time by 82% and MAX5943DEEE+ by 264%, enabling robust operation under high-inertia loads - but requires validation of MOSFET SOA and sense-resistor power rating during extended trip duration.
Availability
MAX5943BEEE+ is available at Aetrix Electronics and suitable for FireWire desktop ports, FireWire peripheral current limiting, and industrial hot-swap modules requiring stable component supply and long-term lifecycle support.
Supply support for MAX5943BEEE+ 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 computing, communications, and industrial applications.
The MAX5943 family was designed specifically for IEEE 1394/FireWire power interface protection - delivering integrated hot-swap, ORing, and UL-recognized circuit-breaker functionality in a single 16-pin QSOP device.
FAQ
What is the primary function of the MAX5943BEEE+ in a FireWire system?
The MAX5943BEEE+ serves as a UL-recognized FireWire/IEEE 1394 protective controller that implements hot-swap current limiting and low-drop power-supply ORing. It controls two external n-channel MOSFETs to safely manage inrush current, provide overcurrent circuit-breaker protection with 5.5ms default timeout, and enable efficient ORing between redundant supplies - all within the 7.5V–37V FireWire voltage range.
How does the MAX5943BEEE+ differ from the MAX5943AEEE+ in current-limit behavior?
The MAX5943BEEE+ implements a non-regulating circuit-breaker function: it holds GATE2 fully enhanced during overcurrent and only disconnects after the timeout expires. In contrast, the MAX5943AEEE+ actively regulates GATE2 to maintain constant current at the programmed limit. This makes MAX5943BEEE+ simpler and lower-cost for applications where brief overcurrents are acceptable, but requires careful MOSFET SOA design during the timeout window.
What is the significance of the ILIM pin configuration on the MAX5943BEEE+?
On the MAX5943BEEE+, the ILIM pin selects the current-threshold voltage applied to the sense amplifier: grounding ILIM sets VTH = 50mV (default), leaving it floating sets 40mV, and connecting to IN sets 60mV. This directly determines the trip current as ITRIP = VTH/RSENSE, enabling precise, resistor-free threshold selection without trimming or calibration.
Can the MAX5943BEEE+ be used outside FireWire applications?
Yes - the MAX5943BEEE+ is applicable to any 7.5V–37V hot-swap or ORing application requiring programmable circuit-breaker protection, including industrial power modules, test equipment, and redundant DC power systems. Its 16-QSOP package, ±5% current-sense accuracy, and −40°C to +85°C rating make it suitable beyond FireWire, though UL recognition specifically covers IEEE 1394 use cases.
How does the MAX5943BEEE+ achieve ultra-fast ORing turn-off?
The MAX5943BEEE+ achieves <100ns ORing turn-off by using a dedicated high-speed comparator that monitors (VIN – VSENSE) against the OR_ADJ-selected threshold (5–12.8mV). When reverse voltage appears at OUT, the comparator triggers immediate GATE1 discharge through an internal low-impedance path - turning off Q1 before reverse current can establish, thereby protecting upstream supplies from backfeed.
MAX5943BEEE+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- 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
MAX5943BEEE+ FAQ
1.How can I place an order for MAX5943BEEE+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX5943BEEE+ 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 MAX5943BEEE+ reliable?
The price and inventory of MAX5943BEEE+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX5943BEEE+ is usually 5 days.
3.What payment methods are accepted for MAX5943BEEE+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX5943BEEE+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX5943BEEE+?
MAX5943BEEE+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX5943BEEE+ 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 MAX5943BEEE+?
For technical support, including MAX5943BEEE+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX5943BEEE+ requirements.
6.How does Aetrix verify that MAX5943BEEE+ is sourced from the original manufacturer or authorized distributors?
All MAX5943BEEE+ 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 MAX5943BEEE+ meets industry standards.
7.What is the process for return or replacement of MAX5943BEEE+?
All MAX5943BEEE+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX5943BEEE+, 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 MAX5943BEEE+ part is unused and in its original packaging.
Return procedure for MAX5943BEEE+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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