Maxim > Products > Hot-Swap, PoE, and Power Switching > MAX5922

MAX5922

+48V, Single-Port Network Power Switch For Power-Over-LAN

Industry's First Single-Port Network Power Switch for Power-over-LAN

Overview

Technical Documents

Ordering Info

Status

Active: In Production.

Description

The MAX5922A/B/C is a single-port network power controller with an integrated power MOSFET, operating from a +32V to +60V supply rail. The device is specifically designed for power-sourcing equipment (PSE) in power-over-LAN applications and is fully compliant to the IEEE® 802.3af standard. The MAX5922 provides power devices (PD) discovery, classification, current limit, and other necessary functions for an IEEE 802.3af compliant PSE.

The MAX5922 is suitable for PSE function in both switch/router systems where the power is delivered to the load through the signal pairs, and in midspan systems where the power is delivered to the load through the spare pairs. In midspan mode, a detection collision avoidance circuit (MAX5922A/C only) provides the necessary back-off timing to prevent fault detections that happen when two different PSEs try to detect and power the same PD. The MAX5922B/C have a detection disable input that can be connected high to disable the detection/classification functions or connected low to enable them.

The MAX5922 features a programmable undervoltage lockout (UVLO) that keeps the device in shutdown until the input voltage exceeds a certain threshold, set to 38V (MAX5922A) or 28V (MAX5922B/C) internally. After successfully discovering and classifying a PD, the MAX5922 enters startup mode. During startup, the MAX5922 limits the output voltage and current slew rate to minimize EMI (electromagnetic interference). The MAX5922 has an integrated 0.45Ω N-channel power MOSFET that provides efficient operation and simplified system design. The MAX5922 monitors and provides current-limit protection to the load at all times. The current limit is programmable using an external current-sensing resistor. The MAX5922 features current-limit foldback and duty-cycle limit to ensure robust operation during load-fault and short-circuit conditions. Fault management allows the part to either latch-off or autorestart after a fault.

The MAX5922 provides POK, active-low ZC, and active-low FAULT status signals to indicate output power is good, zero-current fault, and other faults (overcurrent, overtemperature), respectively. The MAX5922 is available in a 28-pin TSSOP package and is rated over the extended -40°C to +85°C temperature range.

Data Sheet

Download	Rev 0	(PDF, 448kB)
E-Mail

Key Features

IEEE 802.3af Compliant
+32V to +60V Wide Operating Input Range
0.45Ω Integrated Power Switch
Power Device (PD) Detection and Classification
100µA PD Leakage Detection Tolerant
Programmable Current Limit
Zero-Current Detection with Status Output
Detection Collision Avoidance Option for Midspan Application
Input Logic Signals Compatible with 1.8V to 5V CMOS Logic
Separate Analog and Digital Grounds with Up to ±4V Offset
Power-Good Status Output
Overcurrent and Overtemperature Protection with Status Outputs
Current-Limit Foldback with Timeout and Duty-Cycle Control
Latch or Autorestart Fault Management

Applications/Uses

Computer Telephony
Midspan Power Injectors
Power-Over-LAN/Power-Over-MDI (Media-Dependent Interface)
Power-Sourcing Equipment (PSE)
Single-Port Power Injector/Adapter
Switches/Routers with In-Line Power

Key Specifications:

Power Sourcing Equipment

Part Number

IEEE Compliance

High Power Mode

Channels

Port Current Readout

Load Disconnect

Package/Pins

Smallest Available Pckg.
(mm²)

Oper. Temp.
(°C)

Budgetary Price

max w/pins

See Notes

MAX5922

802.3af

TSSOP/28

64.7

-40 to +85

$4.66 @1k

See All Power Sourcing Equipment (8)

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Diagram

Typical Application Circuit

Application Notes

Application Note 3363		New Ethernet Systems Distribute DC Power with Data
Reference Design 3507		IEEE 802.3af-Compliant Single-Port, Power-Sourcing-Equipment Application
Reference Design 3912		Low-Cost, Complete Power Solution for Powered Devices Includes a 12V Buck Converter

Reliability Reports

Reliability Report:	MAX5922.pdf
Show FIT data for:

Software/Models

none

Ordering Information

Filters:

Part Number:

Package:

Temperature:

Tape and Reel

Sample

Part Number	Free Sample	Buy	Status	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
MAX5922AEUI			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5922AEUI+			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5922AEUI+T			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5922AEUI-T			Active	TSSOP;28 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX5922BEUI			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5922BEUI+			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5922BEUI+T			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5922BEUI-T			Active	TSSOP;28 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX5922CEUI			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5922CEUI+			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
Part Number	Free Sample	Buy	Status	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
MAX5922CEUI+T			Active	TSSOP;28 pin;64.7 mm² Outline Drawing:21-0066 (PDF) Land Pattern: 90-0171 (PDF) Use pkgcode/variation: U28+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5922CEUI-T			Active	TSSOP;28 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.