Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Power Over Ethernet (PoE) Controllers

Analog Devices Inc./Maxim Integrated MAX5922CEUI+

Name: MAX5922CEUI+
Brand: Analog Devices Inc./Maxim Integrated
SKU: MAX5922CEUI+
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: MAX5922CEUI+

Manufacturer:: Analog Devices Inc./Maxim Integrated

Category:: Power Over Ethernet (PoE) Controllers

Package:: 28-TSSOP (0.173", 4.40mm Width)

Datasheet:: MAX5922CEUI+.pdf

Description:: IC POE CNTRL 1 CHANNEL 28TSSOP

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,780

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

MAX5922CEUI+ from Maxim Integrated is a single-port IEEE 802.3af-compliant Power Sourcing Equipment (PSE) controller with integrated 0.45Ω N-channel MOSFET, operating from +32V to +60V input. It performs PD detection (19kΩ–26.5kΩ), classification (Class 0–4), programmable current limit (via external R_SENSE), and provides POK/ZC/FAULT status outputs. It is used in midspan power injectors delivering +48V PoE over spare pairs.

For engineers reviewing the MAX5922CEUI+ datasheet, MAX5922CEUI+ pinout, MAX5922CEUI+ application, or MAX5922CEUI+ equivalent, key selection criteria include IEEE 802.3af compliance, detection collision avoidance (enabled in MAX5922C), UVLO threshold (28V), zero-current detection timing (350ms), and 28-pin TSSOP package compatibility with thermal design for -40°C to +85°C operation.

Technical Context

The MAX5922CEUI+ implements full IEEE 802.3af PSE functionality in three sequential modes: detection (two-phase voltage probe at 4V/8V), classification (17.5V forced, 15–26ms duration), and power delivery with slew-rate-controlled startup. Its detection collision avoidance circuit is permanently enabled-unlike MAX5922A (DCA-pin controlled) or MAX5922B (disabled)-making it optimized for midspan systems where multiple PSEs share cabling infrastructure.

It features separate analog (AGND) and digital (DGND) grounds with ±4V offset tolerance, internal charge pump for gate drive, and logic-level translation supporting 1.8V–5V CMOS inputs. Fault management supports latch-off (LATCH = high) or autorestart (LATCH = low), with overcurrent timeout (60ms typ), thermal shutdown (+150°C), and current-limit foldback activated below 18V output.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	+32V to +60V - supports standard 48V PoE infrastructure with headroom for line transients
UVLO Threshold	28V (typ) - prevents startup until supply stabilizes above brownout level; hysteresis 2.5V
Integrated MOSFET R_DS(ON)	0.45Ω (25°C), 0.75Ω (+85°C) - enables efficient single-port power delivery up to ~400mA continuous
PD Detection Range	19kΩ–26.5kΩ resistance, ≤0.6µF capacitance - ensures reliable IEEE 802.3af signature validation
Zero-Current Detection Delay	350ms (typ) - triggers ZC fault after sustained no-load condition, preventing false disconnects
Overcurrent Timeout	60ms (typ) - limits fault duration before shutdown, balancing protection and transient tolerance
Package	28-pin TSSOP - surface-mount footprint with exposed pad for thermal dissipation in compact midspan designs

Pinout & Package

MAX5922CEUI+ is housed in a 28-pin Thin Shrink Small Outline Package (TSSOP) with exposed thermal pad, rated for -40°C to +85°C operation. Pin 1 is marked by a dot; pins 3 and 26 are NC; DRAIN (pins 1–2) and OUT (pins 27–28) are high-current paths requiring appropriate copper pour.

Pin/Terminal	Circuit Role	Design Meaning
IN (Pin 4)	Analog power input	Connects to +32V–+60V rail; bypassed with 47µF/100V + 0.1µF/100V capacitors near pin
DRAIN (Pins 1,2)	MOSFET drain / current-sense return	Connects R_SENSE (0.5Ω) between DRAIN and IN; sets current limit and open-circuit detection threshold
OUT (Pins 27,28)	Power output to PD	Delivers regulated +48V PoE; must be isolated from signal pairs in midspan mode
RDT (Pin 9)	Detection current sense	18.2kΩ resistor to AGND sets PD detection current; 680nF cap filters noise
RCL (Pin 5)	Classification current sense	150Ω resistor to IN sets classification current; float if classification disabled
ZC_EN (Pin 21)	Zero-current detection enable	Logic high enables ZC monitoring post-POK; critical for detecting unplugged PDs
DET_DIS (Pin 24)	Detection disable control	High disables detection/classification - powers ON immediately when EN = high (MAX5922C feature)
DCA (Pin 25)	Detection collision avoidance	Internally tied high in MAX5922C - activates 2.8s back-off delay on failed detection to prevent multi-PSE conflicts

Key Features

Feature	Design Value
IEEE 802.3af compliance	Fully implements detection, classification, and power delivery per Clause 33 - validated for Class 0–4 PDs
Detection collision avoidance	Permanently enabled in MAX5922C - eliminates false fault trips in shared-cable midspan deployments
Programmable current limit	Set via external 0.5Ω±1% R_SENSE; trip threshold 212mV (typ) - enables precise 350mA–450mA load protection
Zero-current detection with status	ZC output asserts low after 350ms no-load - allows host MCU to safely de-energize port without manual polling
Separate AGND/DGND with ±4V offset	Enables robust noise isolation between analog sensing and digital control - critical for EMI-sensitive PoE environments
Startup slew-rate control	dV_OUT/dt ≤ 100V/ms, dI_OUT/dt ≤ 35A/ms - minimizes conducted EMI during power-up into capacitive PD loads

Applications

Midspan Power Injector	Single-Port PoE Adapter
Use Scenario: Standalone 48V power injector inserted between Ethernet switch and endpoint device (e.g., IP camera), delivering power over spare wire pairs. IC Role / Device Role / Timing Role: Primary PSE controller managing detection, classification, and regulated power delivery; handles collision avoidance during multi-injector deployment. Use Value: Enables drop-in PoE capability without switch modification; MAX5922CEUI+'s permanent DCA prevents detection conflicts when multiple injectors serve same cable plant.	Use Scenario: Compact wall-mounted or desktop adapter converting AC to IEEE 802.3af-compliant 48V PoE for Wi-Fi access points or VoIP phones. IC Role / Device Role / Timing Role: Single-chip PSE solution integrating MOSFET, sensing, and status signaling - replaces discrete FET + controller designs. Use Value: Reduces BOM count and layout area; 0.45Ω R_DS(ON) minimizes heat rise in enclosed enclosures; 28-pin TSSOP supports automated assembly.
Computer Telephony System	Industrial Ethernet Node
Use Scenario: Embedded PoE port in enterprise phone base station or call-center gateway, powering remote handsets or headsets. IC Role / Device Role / Timing Role: IEEE-compliant PSE interface with ZC_EN and FAULT outputs enabling host microcontroller to monitor port state and initiate safe disconnect. Use Value: ZC detection (350ms delay) prevents nuisance resets during brief handset disconnection; POK confirms stable output before enabling downstream logic.	Use Scenario: Ruggedized Ethernet I/O module in factory automation, powering sensors or actuators over extended cable runs. IC Role / Device Role / Timing Role: Robust PSE controller tolerant of industrial voltage ripple and temperature swings (-40°C to +85°C). Use Value: Wide +32V–+60V input range accommodates unregulated 48V DC supplies; thermal shutdown (+150°C) and foldback protect against sustained overload in harsh environments.

Midspan Power Injector

Single-Port PoE Adapter

Use Scenario: Standalone 48V power injector inserted between Ethernet switch and endpoint device (e.g., IP camera), delivering power over spare wire pairs.

IC Role / Device Role / Timing Role: Primary PSE controller managing detection, classification, and regulated power delivery; handles collision avoidance during multi-injector deployment.

Use Value: Enables drop-in PoE capability without switch modification; MAX5922CEUI+'s permanent DCA prevents detection conflicts when multiple injectors serve same cable plant.

Use Scenario: Compact wall-mounted or desktop adapter converting AC to IEEE 802.3af-compliant 48V PoE for Wi-Fi access points or VoIP phones.

IC Role / Device Role / Timing Role: Single-chip PSE solution integrating MOSFET, sensing, and status signaling - replaces discrete FET + controller designs.

Use Value: Reduces BOM count and layout area; 0.45Ω R_DS(ON) minimizes heat rise in enclosed enclosures; 28-pin TSSOP supports automated assembly.

Computer Telephony System

Industrial Ethernet Node

Use Scenario: Embedded PoE port in enterprise phone base station or call-center gateway, powering remote handsets or headsets.

IC Role / Device Role / Timing Role: IEEE-compliant PSE interface with ZC_EN and FAULT outputs enabling host microcontroller to monitor port state and initiate safe disconnect.

Use Value: ZC detection (350ms delay) prevents nuisance resets during brief handset disconnection; POK confirms stable output before enabling downstream logic.

Use Scenario: Ruggedized Ethernet I/O module in factory automation, powering sensors or actuators over extended cable runs.

IC Role / Device Role / Timing Role: Robust PSE controller tolerant of industrial voltage ripple and temperature swings (-40°C to +85°C).

Use Value: Wide +32V–+60V input range accommodates unregulated 48V DC supplies; thermal shutdown (+150°C) and foldback protect against sustained overload in harsh environments.

Equivalent & Alternatives

The following parts are listed as comparable options for similar IEEE 802.3af PSE applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX5922AEUI+	UVLO = 38V (vs. 28V); DCA enabled only when DCA pin = high; no DET_DIS pin	Suitable for switch-integrated PSE where higher UVLO prevents premature startup on unstable rails	Select MAX5922AEUI+ when system input has high ripple or slow ramp-up; avoid if midspan collision avoidance must be unconditional
LT4275IMS#PBF	IEEE 802.3at (PoE+) compliant; supports up to 30W; requires external MOSFET; 16-pin MSOP	Required for Class 4 PDs needing >15.4W; adds complexity but enables higher-power endpoints	Choose LT4275IMS#PBF only when upgrading to PoE+; MAX5922CEUI+ remains optimal for cost-sensitive, single-port 802.3af designs

Compared with MAX5922AEUI+, MAX5922CEUI+ offers lower UVLO and guaranteed DCA - ideal for midspan injectors on stable 48V rails. Versus LT4275, it trades PoE+ capability for integration, smaller footprint, and lower BOM cost in 802.3af-limited applications.

Availability

MAX5922CEUI+ is available at Aetrix Electronics and suitable for midspan power injectors, single-port PoE adapters, computer telephony gateways, and industrial Ethernet nodes requiring stable component supply, long-term lifecycle support, and IEEE 802.3af compliance.

Supply support for MAX5922CEUI+ 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 industrial, communications, and computing applications.

The MAX5922 product line delivers fully integrated, standards-compliant PSE controllers targeting cost-effective, space-constrained power-over-Ethernet implementations - especially midspan and adapter form factors.

FAQ

What is the UVLO threshold for MAX5922CEUI+ and how is it set?

The MAX5922CEUI+ has a fixed undervoltage lockout (UVLO) threshold of 28V (typical), with 2.5V hysteresis. Unlike the MAX5922A variant, this threshold is not adjustable - it is internally trimmed and does not require external resistor dividers. The device remains in shutdown until VIN exceeds 28V, ensuring reliable startup only after the 48V supply stabilizes. This value is confirmed in the Electrical Characteristics table under "Default VIN UVLO" for MAX5922B/C variants, and MAX5922CEUI+ is a MAX5922C-grade part.

Does MAX5922CEUI+ support detection collision avoidance, and how is it configured?

Yes, MAX5922CEUI+ permanently enables detection collision avoidance (DCA) - no external pin control is required. When a PD detection fails, the device automatically enters a 2.8s high-impedance back-off period before retrying, preventing simultaneous detection attempts by multiple PSEs on the same cable. This behavior is intrinsic to the MAX5922C version and distinguishes it from MAX5922A (DCA pin-controlled) and MAX5922B (DCA disabled). The DCA pin (Pin 25) is internally tied high in MAX5922CEUI+.

How does MAX5922CEUI+ handle PD classification, and what classes does it support?

MAX5922CEUI+ fully supports IEEE 802.3af Class 0 through Class 4 PD classification. It applies a 17.5V classification voltage for 15–26ms, measures resulting current, and reports the result via CL0–CL2 open-drain outputs. Thresholds are fixed: Class 0–1 at 6.5mA, Class 1–2 at 14.5mA, Class 2–3 at 23mA, and Class 3–4 at 33mA. Classification is enabled by pulling CLASS high (to VDIG); it can be disabled by grounding CLASS, though MAX5922CEUI+ retains detection capability regardless.

What is the purpose of the ZC_EN pin on MAX5922CEUI+, and when should it be asserted?

ZC_EN (Pin 21) enables or disables the zero-current detection circuit. When pulled high to DGND, ZC monitoring activates immediately after POK goes high - asserting ZC low if load current remains below 3.75mV across R_SENSE for 350ms (typ). This signals unplugged or faulty PDs. It should be asserted high in all applications requiring automatic port de-energization; leaving it low disables ZC entirely, requiring software polling of current sense instead. MAX5922CEUI+ relies on ZC_EN to provide deterministic fault reporting without host intervention.

Can MAX5922CEUI+ operate with a 1.8V digital supply, and which pins are affected?

Yes, MAX5922CEUI+ supports 1.8V to 5.5V digital logic levels on VDIG (Pin 23), and all digital inputs - EN, LATCH, DET_DIS, DCA, CLASS, and ZC_EN - scale their thresholds proportionally. At VDIG = 1.8V, VIH is 1.26V and VIL is 0.8V; at VDIG = 5V, VIH is 3.5V and VIL is 0.8V. This allows direct interfacing with low-voltage MCUs without level shifters. However, analog functions (detection, classification, current sensing) remain independent of VDIG and reference AGND/IN.

MAX5922CEUI+ Specifications

Product attributes: Attribute value

Manufacturer:: Analog Devices Inc./Maxim Integrated

Series:: -

Package/Case:: 28-TSSOP (0.173", 4.40mm Width)

Packaging:: Tube

Product Status:: Active

Type:: Controller (PSE)

Number of Channels:: 1

Power - Max:: 15.4 W

Internal Switch(s):: Yes

Auxiliary Sense:: No

Standards:: 802.3af (PoE)

Voltage - Supply:: 32V ~ 60V

Current - Supply:: 1mA

Operating Temperature:: -40°C ~ 85°C

Mounting Type:: Surface Mount

Supplier Device Package:: 28-TSSOP

MAX5922CEUI+ FAQ

1.How can I place an order for MAX5922CEUI+ through Aetrix?

Please submit a Request for Quotation (RFQ) for MAX5922CEUI+ 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 MAX5922CEUI+ reliable?

The price and inventory of MAX5922CEUI+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX5922CEUI+ is usually 5 days.

3.What payment methods are accepted for MAX5922CEUI+?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX5922CEUI+ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MAX5922CEUI+?

MAX5922CEUI+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MAX5922CEUI+ 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 MAX5922CEUI+?

For technical support, including MAX5922CEUI+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX5922CEUI+ requirements.

6.How does Aetrix verify that MAX5922CEUI+ is sourced from the original manufacturer or authorized distributors?

All MAX5922CEUI+ 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 MAX5922CEUI+ meets industry standards.

7.What is the process for return or replacement of MAX5922CEUI+?

All MAX5922CEUI+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX5922CEUI+, 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 MAX5922CEUI+ part is unused and in its original packaging.

Return procedure for MAX5922CEUI+:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…