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Analog Devices Inc./Maxim Integrated MAX5953DUTM+
- Part No.:
- MAX5953DUTM+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Power Over Ethernet (PoE) Controllers
- Package:
- 48-WFQFN Exposed Pad
- Datasheet:
-
MAX5953DUTM+.pdf
- Description:
- IC POE CNTRL 1 CHANNEL 48TQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
The MAX5953DUTM+ from Maxim Integrated is an IEEE 802.3af-compliant Powered Device (PD) interface and voltage-mode PWM controller IC with integrated high-voltage power MOSFETs, designed for PoE-powered endpoints requiring up to 15W output. It delivers PD detection/classification signatures, programmable inrush current control, and a clamped two-switch DC-DC converter operating from 11V–76V input. It is used in security cameras, IP phones, and wireless access nodes where robust PoE handshaking and efficient local DC-DC conversion are required.
For engineers reviewing the MAX5953DUTM+ datasheet, MAX5953DUTM+ pinout, MAX5953DUTM+ application, or MAX5953DUTM+ equivalent, this page provides verified technical context, confirmed pin functions, real-world application mappings, and validated alternative parts - all specific to the MAX5953D variant's fixed UVLO threshold (34.3V–36.9V), active-low PGOOD, and thermally enhanced 48-pin TQFN package.
Technical Context
The MAX5953DUTM+ implements a dual-function architecture: its PD interface performs IEEE 802.3af-compliant detection (≤10µA leakage offset), classification (Class 0–4 via RCLASS resistor), and isolation switching using an integrated n-channel MOSFET (RON ≤ 1.5Ω), while its DC-DC controller operates a two-switch forward/flyback topology with integrated 0.4Ω high-voltage power FETs and feed-forward voltage-mode control. The device uses separate ground domains (VEE for PD interface, GND/PGND for DC-DC stage) and features independent UVLO circuits - one fixed-threshold (34.3V–36.9V) for PD power-on and another (1.14V–1.38V) for DC-DC operation.
It supports synchronous rectification via a look-ahead PPWM signal (110ns propagation delay), includes soft-start (33µA CSS current), and integrates fault protection with programmable hiccup-mode short-circuit response (FLTINT trip at 2.7V). Switching frequency is adjustable from 250kHz up to 500kHz via RTCT, enabling compact magnetics and >90% efficiency with synchronous rectification.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| PD Standard Compliance | Fully compliant with IEEE 802.3af; supports Class 0–4 classification via external RCLASS resistor. |
| UVLO Threshold (PD Mode) | Fixed 34.3V–36.9V turn-on / 30V turn-off; optimized for legacy pre-802.3af PSE compatibility. |
| PGOOD Polarity | Active-low, open-drain output referenced to VEE - distinct from MAX5953A/B/C variants. |
| DC-DC Input Range | 11V–76V HVIN; enables operation across full PoE voltage range including underloaded or long-cable conditions. |
| Output Power Capability | Up to 15W; achieved using integrated 0.4Ω power MOSFETs and clamped two-switch topology for leakage energy recovery. |
| Switching Frequency | Programmable 250kHz–500kHz via RTCT; allows trade-off between efficiency and size of external magnetics/capacitors. |
| Thermal Package | 48-pin thermally enhanced thin QFN (7mm × 7mm); 2.22W continuous power dissipation at TA = +70°C (θJA = 36°C/W). |
Pinout & Package
MAX5953DUTM+ is housed in a 48-pin, 7mm × 7mm thermally enhanced thin QFN package (T4877-6) with exposed paddle connected to VEE. The package supports high-power PoE applications with low thermal resistance (θJA = 36°C/W) and requires soldering the EP pad to a VEE-connected copper plane for optimal heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 4, V+ | Positive PD input supply | Receives PoE input (up to +90V relative to VEE); connects to transformer center-tap or bridge rectifier output. |
| 10–11, VEE | Negative PD input supply / isolation FET source | Reference for PD interface; source terminal of internal isolation MOSFET; must connect to system ground or return path. |
| 15–16, OUT | Isolated PD output node | Drain of internal isolation MOSFET; supplies downstream DC-DC stage; connects to HVIN and GND. |
| 18, PGOOD | Active-low PD power-good indicator | Open-drain output referenced to VEE; asserts low when VOUT ≥ 1.2V above VEE and VGATE ≥ 5V; used to enable CSS or DCUVLO. |
| 39, HVIN | DC-DC converter primary input | Receives regulated PoE-derived voltage (11V–76V); referenced to GND; bypassed externally for high-frequency noise suppression. |
| 41, REGOUT | Internal LDO output (8.75V–11.0V) | Supplies gate drivers and bias for DC-DC stage; stable as long as HVIN exceeds DCUVLO threshold (1.14V–1.38V). |
| 42, RTCT | Oscillator timing input | Connects to resistor-to-REGOUT and capacitor-to-GND to set switching frequency (250kHz–500kHz); ±1µA bias current. |
| 43, FLTINT | Fault integration capacitor node | Charged at 80µA during overcurrent; disables PWM when voltage reaches 2.7V; resumes at 1.9V after external RC discharge. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed UVLO for legacy PSE support | 34.3V–36.9V turn-on threshold ensures reliable startup with older non-802.3af-compliant power sourcing equipment. |
| Active-low PGOOD signaling | Eliminates need for external level-shifting when interfacing with VEE-referenced logic or enable inputs on downstream regulators. |
| Integrated isolation MOSFET | 0.6Ω–1.5Ω RON enables low-loss PD isolation during detection/classification and controlled inrush via external GATE–OUT capacitor. |
| Look-ahead PPWM output | 110ns propagation delay enables precise timing of secondary-side synchronous rectifiers, improving efficiency beyond 90%. |
| Two-switch clamped topology | Recovers magnetizing and leakage inductive energy, reducing stress on MOSFETs and increasing reliability in flyback/forward modes. |
| Independent ground domains | VEE (PD interface) and GND/PGND (DC-DC stage) separation prevents noise coupling and simplifies PCB layout for mixed-signal PoE systems. |
Applications
| IP Phones | Security Cameras |
|---|---|
|
Use Scenario: Powered VoIP endpoint requiring reliable PoE handshake, low-noise local regulation, and standby current <1mA. IC Role / Device Role: Full PD interface + DC-DC controller; handles detection, classification, isolation, and 5V/3.3V local conversion. Use Value: Fixed UVLO ensures compatibility with enterprise switches deployed before 2003; active-low PGOOD directly enables low-quiescent PMICs. |
Use Scenario: Outdoor PTZ camera with heater, IR LEDs, and image sensor needing 12V/5V rails and thermal shutdown. IC Role / Device Role: Primary PoE interface and isolated DC-DC power stage; manages inrush, overtemperature (160°C shutdown), and short-circuit hiccup. Use Value: Integrated 0.4Ω power FETs and clamped topology deliver 15W efficiently; exposed paddle aids thermal management in sealed enclosures. |
| Wireless Access Nodes | Internet Appliances |
|
Use Scenario: Dual-band 802.11ac access point drawing burst power up to 12W while maintaining RF signal integrity. IC Role / Device Role: PD interface with low EMI DC-DC conversion; separates analog/digital grounds via VEE/GND partitioning. Use Value: Feed-forward voltage-mode control rejects input transients from cable impedance variations; 500kHz operation minimizes EMI filter size. |
Use Scenario: Smart home hub with Zigbee/Z-Wave radios, USB ports, and Ethernet, requiring multiple isolated rails and BOM reduction. IC Role / Device Role: Single-chip PoE PD + DC-DC solution replacing discrete controllers, MOSFETs, and gate drivers. Use Value: 48-pin TQFN integrates all core functions; eliminates 12+ external components versus discrete implementations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Powered Device interface and DC-DC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX5953CUTM+ | Adjustable UVLO (via external resistor divider); active-low PGOOD same as MAX5953DUTM+. | Suitable for new designs requiring field-programmable turn-on voltage; not drop-in compatible due to UVLO pin function change (UVLO pin used vs. N.C. on MAX5953D). | Select MAX5953CUTM+ only if UVLO threshold tuning is needed; MAX5953DUTM+ is preferred for fixed-threshold legacy PSE deployments. |
| LT4275IMS#PBF | IEEE 802.3at/af-compliant PD interface only (no integrated DC-DC controller or power FETs); requires external flyback controller. | Used where higher power (>15W) or design flexibility justifies multi-chip solution; lacks integrated power stage and synchronous rectifier drive. | Choose LT4275IMS#PBF when upgrading to PoE+ or when custom DC-DC topology (e.g., active clamp) is required; MAX5953DUTM+ offers single-chip simplicity. |
Compared with MAX5953CUTM+, MAX5953DUTM+ removes UVLO configurability for guaranteed legacy PSE interoperability; compared with LT4275IMS#PBF, it integrates the entire power conversion chain - eliminating external MOSFETs, gate drivers, and controller ICs - reducing BOM count and layout complexity for 15W-class PoE endpoints.
Availability
MAX5953DUTM+ is available at Aetrix Electronics and suitable for security cameras, IP phones, and wireless access nodes requiring stable component supply, long-term industrial lifecycle support, and guaranteed lead-free compliance.
Supply support for MAX5953DUTM+ 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 MAX5953 family targets IEEE 802.3af PoE-powered devices, integrating both PD interface logic and DC-DC power conversion to reduce bill-of-materials and simplify design of powered endpoints such as VoIP phones and surveillance cameras.
FAQ
What is the UVLO threshold behavior of the MAX5953DUTM+?
The MAX5953DUTM+ features a fixed undervoltage lockout threshold of 34.3V–36.9V for power-on and 30V for power-off, optimized for compatibility with legacy pre-802.3af power sourcing equipment. Unlike the MAX5953A/C variants, its UVLO pin is unconnected (N.C.), so no external resistor divider is required or supported - ensuring consistent startup behavior across manufacturing lots and temperature ranges.
How does the PGOOD output differ on the MAX5953DUTM+ compared to other MAX5953 variants?
The MAX5953DUTM+ uses an active-low, open-drain PGOOD output referenced to VEE - unlike the MAX5953A/B (active-high, referenced to OUT) and MAX5953C (also active-low but identical in polarity). This configuration allows direct connection to enable inputs of VEE-referenced regulators without level-shifting circuitry, simplifying power sequencing in cost-sensitive PoE endpoints.
Can the MAX5953DUTM+ be used in a flyback configuration?
Yes, the MAX5953DUTM+ supports both forward and flyback topologies via its clamped two-switch DC-DC architecture. Its integrated 0.4Ω power MOSFETs, programmable switching frequency (250kHz–500kHz), and look-ahead PPWM signal make it suitable for isolated flyback designs delivering up to 15W - commonly used in PoE-powered security cameras and access points requiring galvanic isolation.
What is the role of the exposed paddle (EP) on the MAX5953DUTM+ package?
The exposed paddle (EP) on the MAX5953DUTM+ is internally unconnected and must be externally soldered to a VEE-referenced copper pour. This thermal pad reduces junction-to-board thermal resistance, enabling the device to sustain its rated 2.22W power dissipation at +70°C ambient - critical for compact, sealed PoE devices like outdoor cameras where airflow is limited.
Does the MAX5953DUTM+ support synchronous rectification?
Yes, the MAX5953DUTM+ includes a dedicated PPWM output that leads the internal power MOSFET gate drive by ~110ns, enabling precise timing control of external synchronous rectifiers. When paired with low-VF Schottky diodes or MOSFETs, this feature helps achieve >90% system efficiency - especially valuable in thermally constrained 15W PoE applications such as IP phones and wireless access nodes.
MAX5953DUTM+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 48-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- Controller (PD), DC/DC
- Number of Channels:
- 1
- Power - Max:
- 15 W
- Internal Switch(s):
- Yes
- Auxiliary Sense:
- No
- Standards:
- 802.3af (PoE)
- Voltage - Supply:
- 11V ~ 76V
- Current - Supply:
- 400µA
- Operating Temperature:
- 0°C ~ 85°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-TQFN (7x7)
MAX5953DUTM+ FAQ
1.How can I place an order for MAX5953DUTM+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX5953DUTM+ 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 MAX5953DUTM+ reliable?
The price and inventory of MAX5953DUTM+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX5953DUTM+ is usually 5 days.
3.What payment methods are accepted for MAX5953DUTM+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX5953DUTM+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX5953DUTM+?
MAX5953DUTM+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX5953DUTM+ 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 MAX5953DUTM+?
For technical support, including MAX5953DUTM+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX5953DUTM+ requirements.
6.How does Aetrix verify that MAX5953DUTM+ is sourced from the original manufacturer or authorized distributors?
All MAX5953DUTM+ 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 MAX5953DUTM+ meets industry standards.
7.What is the process for return or replacement of MAX5953DUTM+?
All MAX5953DUTM+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX5953DUTM+, 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 MAX5953DUTM+ part is unused and in its original packaging.
Return procedure for MAX5953DUTM+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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