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Analog Devices Inc./Maxim Integrated MAX5992BETG+
- Part No.:
- MAX5992BETG+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
MAX5992BETG+.pdf
- Description:
- IC MULTISOURCE CONTROLLER QFN
- Quantity:
- Payment:
- Shipping:
Inventory:225
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Product details
Overview
The MAX5992BETG+ from Maxim Integrated is a high-power IEEE 802.3af/at-compliant powered device (PD) controller for Power-over-Ethernet systems, featuring 35.4V PoE UVLO threshold, 6.5s sleep mode delay, integrated active FET bridge control, 2-event classification support, and RJ45 12V mode operation - enabling robust multi-PD redundancy and FTTH/FTTB deployments in IP security cameras and wireless access nodes.
For engineers reviewing the MAX5992BETG+ datasheet, MAX5992BETG+ pinout, MAX5992BETG+ application, or MAX5992BETG+ equivalent, this page delivers verified technical context, exact pin functions, real-world use-value per application, and two validated alternative PD controllers with documented functional and selection differences.
Technical Context
The MAX5992BETG+ implements dual-stage inrush control with selectable 800mA/1.9A current limits and foldback protection, synchronized via RDCY_SEL for multi-PD redundancy. Its active FET bridge uses VIN1/VIN2 differential sensing (≥100mV threshold) to drive four external MOSFET gates (NDR1/NDR2/PDR1/PDR2) with 8–11V gate drive voltage and 500kΩ gate-source resistance.
It supports intelligent maintain power signature (MPS) with 10–14mA amplitude, 75% duty cycle, and programmable enable/disable timing (76–98ms / 205–265ms), while delivering ultra-low-power sleep mode with 250Hz LED pulsing (10–23.5mA) and SIG_OK synchronization for 2x2P PD systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| PoE UVLO Threshold | 35.4V (MAX5992B-specific; enables lower-voltage PoE startup vs. MAX5992A's 38.6V) |
| Sleep Mode Delay | 6.5s (programmable SL hold time before entering sleep/ultra-low-power sleep) |
| RJ45 12V Mode | Enabled with 8.7V threshold and 1.8s turn-on delay - supports auxiliary 12V PoE sourcing |
| Classification Support | IEEE 802.3af/at 2-event classification (Class 0–5); mark event at 10.8V, reset at 4V |
| MPS Current | 12mA typical (10–14mA range), 75% duty cycle - sustains PSE link during low-power states |
| Gate Drive Capability | 8–11V output swing, 44mA strong pulldown current - ensures fast, reliable isolation FET switching |
| Thermal Protection | 150°C shutdown with 20°C hysteresis - prevents latch-up during sustained overload |
Pinout & Package
MAX5992BETG+ is housed in a 24-pin, 4mm × 4mm TQFN package with exposed pad (EP) connected to VSS for thermal management. The package is rated for -40°C to +85°C operation and features 36°C/W junction-to-ambient thermal resistance on a four-layer board.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Positive supply input | Connects to rectified positive output of active FET bridge; requires ≥68nF bypass capacitor to VSS |
| DET | Detection resistor input | Accepts 24.9kΩ signature resistor to VSS for IEEE-compliant PD detection |
| CLS | Classification resistor input | Sets Class 0–5 current via external RCLS (e.g., 21.5Ω for Class 5) |
| ADJ_UVLO | UVLO select input | Unconnected = 35.4V PoE UVLO; tied to VSS = 20.8V industrial UVLO |
| WAD_SEL | Wall adapter behavior select | Unconnected = prioritize wall adapter; grounded = only switch if wall adapter > PoE voltage |
| CL_SEL | Current-limit select input | Unconnected = 800mA inrush limit; grounded = 1.9A limit for high-power PDs |
| VSS | Negative supply input | Connects to rectified negative output of active FET bridge and EP |
| SENSE | Current-sense positive terminal | Connects to source of external isolation MOSFET and 100mΩ sense resistor to VSS |
| GATE | Isolation MOSFET gate driver | Drives external N-channel MOSFET gate with 8–11V swing and 44mA pulldown |
| RTN | Drain-sense input | Monitors MOSFET drain voltage; used for redundancy diode connection in multi-PD systems |
| WAD | Wall adapter detector input | Detects >8V wall adapter presence relative to RTN; triggers seamless switchover |
| PG | Power-good indicator output | Open-drain signal referenced to VDD; drives DC-DC enable pin via resistor divider |
| 2EC | 2-event classification/wall adapter detect | 1.5mA current sink activated on Type 2 PSE probe or wall adapter detection |
| RDCY_SEL | Redundancy-select input | Grounded = enables multi-PD/FTTH inrush synchronization; unconnected = single-PD mode |
| SL | Sleep mode enable input | Falling edge (MAX5992A) or 6.5s low hold (MAX5992B) initiates sleep; sets LED current via RSL |
| ULP | Ultra-low-power sleep enable/wake | Low assertion + SL low enables ULP mode; falling edge wakes device from sleep/ULP |
| LED | LED driver output | Sources 250Hz, 25% duty-cycle current (10–23.5mA) during sleep/MPS; RSL sets amplitude |
| SIG_OK | Signal-OK input/output | Internally pulled up to VDD; synchronizes inrush across 2x2P PDs when cross-connected |
| VIN1 / VIN2 | Active FET bridge inputs | Differential sensing inputs (≥100mV threshold) that determine nFET/pFET activation sequence |
| NDR1 / NDR2 | nFET gate-control outputs | Drive gates of external n-channel FETs in active bridge; logic-level compatible |
| PDR1 / PDR2 | pFET gate-control outputs | Drive gates of external p-channel FETs in active bridge; referenced to VDD/VSS |
| EP | Exposed thermal pad | Must be soldered to VSS plane for thermal dissipation; internal resistive path to VSS |
Key Features
| Feature | Design Value |
|---|---|
| IEEE 802.3af/at & UPoE compliance | Full hardware implementation of detection, classification (0–5), and 2-event signaling - no firmware required |
| Active FET bridge control | Four independent gate drivers (NDR1/NDR2/PDR1/PDR2) with polarity-aware switching for full-bridge rectification |
| Intelligent MPS with timing control | Programmable 76–98ms enable and 205–265ms disable windows ensure stable PSE handshake during low-power states |
| Selectably redundant inrush control | RDCY_SEL pin configures synchronized multi-PD startup or independent FTTH/FTTB sequencing |
| Seamless wall adapter transition | WAD_SEL pin defines priority logic (voltage-based or presence-based) for automatic PoE ↔ wall adapter switchover |
| Ultra-low-power sleep with LED feedback | 250Hz LED pulsing (10–23.5mA) maintained during sleep/ULP modes - provides visual status without waking system |
Applications
| IP Security Cameras (IPC) | Wireless Access Nodes |
|---|---|
|
Use Scenario: Outdoor PoE-powered IPC with dual power sources (PoE + local 12V adapter) and thermal throttling requirements. IC Role / Device Role / Timing Role: PD controller managing detection/classification, active bridge rectification, MPS maintenance, and thermal shutdown at 150°C. Use Value: 6.5s SL delay prevents false sleep triggers from transient load dips; RJ45 12V mode enables failover to local 12V during PoE brownouts. |
Use Scenario: High-density Wi-Fi 6 access point with multi-PD redundancy and 2x2P synchronization for carrier-grade uptime. IC Role / Device Role / Timing Role: Synchronized PD controller using SIG_OK interconnection and RDCY_SEL for coordinated inrush across dual Ethernet ports. Use Value: 2-event classification ensures correct Type 2 PSE allocation; active FET bridge eliminates external diode losses, improving efficiency by ~12%. |
| Fiber-to-the-Home (FTTH) | Femtocell Base Stations |
|
Use Scenario: Residential ONT with PoE backup, requiring low standby power and reliable wall adapter switchover. IC Role / Device Role / Timing Role: PD controller executing ultra-low-power sleep mode with 250Hz LED indication and WAD_SEL-configured priority logic. Use Value: ULP mode draws <15µA quiescent current while sustaining MPS; WAD_SEL grounding ensures wall adapter only powers unit when >PoE voltage. |
Use Scenario: Small-cell base station deployed in temperature-variable environments with strict thermal safety mandates. IC Role / Device Role / Timing Role: PD controller enforcing 150°C thermal shutdown with 20°C hysteresis and foldback current limiting above 40V output. Use Value: Foldback start at 11V prevents thermal runaway during short-circuit events; 20°C hysteresis avoids oscillation near trip point. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar powered device controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX5995ETG+ | Higher 42.5V PoE UVLO; no RJ45 12V mode; 3.5s sleep delay; supports only Class 0–4 | Better suited for industrial PoE where higher UVLO margin is needed; lacks FTTH/12V auxiliary support | Select MAX5995ETG+ when operating in noisy 48V PoE environments requiring extra UVLO headroom and no wall adapter interface |
| LT4275IMS#PBF | IEEE 802.3bt-compliant (up to 90W); 35.5V UVLO; no integrated active bridge drivers; requires external MOSFET gate logic | Enables higher-power PDs (e.g., PTZ cameras); adds complexity with external FET control but supports next-gen PoE standards | Choose LT4275IMS#PBF when upgrading to 802.3bt and accepting added layout complexity for >60W capability |
Compared with MAX5992BETG+, MAX5995ETG+ offers higher UVLO margin but omits RJ45 12V and 2-event Class 5 support, while LT4275IMS#PBF enables 802.3bt compliance at the cost of external bridge control - making MAX5992BETG+ optimal for cost-sensitive, dual-source 802.3at PDs needing integrated bridge and redundancy sync.
Availability
MAX5992BETG+ is available at Aetrix Electronics and suitable for IP security cameras, wireless access nodes, and fiber-to-the-home (FTTH) equipment requiring stable component supply, multi-PD redundancy, and seamless wall adapter fallback.
Supply support for MAX5992BETG+ 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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, communications, and computing applications.
The MAX5992BETG+ belongs to Maxim's Power-over-Ethernet PD controller product line, engineered specifically for high-reliability, multi-source PoE endpoints requiring IEEE 802.3af/at compliance, active bridge integration, and intelligent power management.
FAQ
What is the PoE UVLO threshold for MAX5992BETG+?
The MAX5992BETG+ has a nominal PoE under-voltage lockout (UVLO) threshold of 35.4V, which is lower than the MAX5992A's 38.6V. This allows earlier startup in marginal PoE conditions. An industrial UVLO option of 20.8V is enabled by grounding the ADJ_UVLO pin. Both thresholds include built-in hysteresis (3.2V standard, 1.8V industrial) to prevent chatter during voltage transitions.
How does MAX5992BETG+ support seamless wall adapter switchover?
The MAX5992BETG+ detects wall adapter presence via the WAD pin (threshold: 8V referenced to RTN). When WAD_SEL is unconnected, it prioritizes the wall adapter upon detection; when WAD_SEL is grounded, it switches only if the wall adapter voltage exceeds the PoE input. This logic, combined with PG and 2EC signaling, enables glitch-free handover without interrupting downstream DC-DC operation.
What is the purpose of the SIG_OK pin on MAX5992BETG+?
The SIG_OK pin on MAX5992BETG+ serves as both an input and output for synchronizing inrush behavior across multiple PDs. When driven low (e.g., by another MAX5992BETG+), it triggers inrush mode. In 2x2P PD configurations, connecting SIG_OK pins between devices ensures simultaneous startup and avoids current surges that could trip upstream PSE current limits.
Does MAX5992BETG+ support IEEE 802.3bt (PoE++)?
No, MAX5992BETG+ is compliant with IEEE 802.3af (PoE) and 802.3at (PoE+) standards only. It supports up to Class 5 (up to ~60W) but does not implement the four-pair power delivery, autoclass, or 90W capabilities defined in 802.3bt. For 802.3bt, consider Analog Devices' LT4275 or MAX5991 series instead of MAX5992BETG+.
How is the LED driver configured on MAX5992BETG+?
The LED pin on MAX5992BETG+ sources a 250Hz, 25% duty-cycle current during sleep, ultra-low-power sleep, and MPS modes. Its amplitude (10–23.5mA) is set by an external resistor RSL between SL and VSS, calculated as ILED (A) = 645.75/(RSL + 1200). No LED connection requires tying LED to VSS - leaving it floating is prohibited.
MAX5992BETG+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Controller (PD)
- Number of Channels:
- 1
- Power - Max:
- -
- Internal Switch(s):
- Yes
- Auxiliary Sense:
- Yes
- Standards:
- 802.3at (PoE+), 802.3af (PoE)
- Voltage - Supply:
- 60V
- Current - Supply:
- 1.5mA
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-TQFN (4x4)
MAX5992BETG+ FAQ
1.How can I place an order for MAX5992BETG+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX5992BETG+ 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 MAX5992BETG+ reliable?
The price and inventory of MAX5992BETG+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX5992BETG+ is usually 5 days.
3.What payment methods are accepted for MAX5992BETG+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX5992BETG+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX5992BETG+?
MAX5992BETG+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX5992BETG+ 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 MAX5992BETG+?
For technical support, including MAX5992BETG+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX5992BETG+ requirements.
6.How does Aetrix verify that MAX5992BETG+ is sourced from the original manufacturer or authorized distributors?
All MAX5992BETG+ 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 MAX5992BETG+ meets industry standards.
7.What is the process for return or replacement of MAX5992BETG+?
All MAX5992BETG+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX5992BETG+, 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 MAX5992BETG+ part is unused and in its original packaging.
Return procedure for MAX5992BETG+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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