Maxim > Products > Hot-Swap, PoE, and Power Switching > MAX5940, MAX5940A, MAX5940B

MAX5940, MAX5940A, MAX5940B

IEEE 802.3af PD Interface Controller for Power-Over-Ethernet

Industry's First IEEE 802.3af-Compliant Power-Device Interface Controllers with Adjustable Undervoltage Lockout

Overview

Technical Documents

Ordering Info

Status

Active: In Production.

Description

The MAX5940A/MAX5940B/MAX5940C/MAX5940D provide complete interface function for a powered device (PD) to comply with the IEEE® 802.3af standard in a power-over-ethernet system. MAX5940A/MAX5940B/MAX5940C/MAX5940D provide the PD with a detection signature, a classification signature, and an integrated isolation switch with programmable inrush current control. These devices also feature power-mode undervoltage lockout (UVLO) with wide hysteresis and power-good outputs. The MAX5940A/MAX5940B are available with an absolute maximum rating of 80V and the MAX5940C/MAX5940D are rated for an absolute maximum rating of 90V.

An integrated MOSFET provides PD isolation during detection and classification. All devices guarantee a leakage current offset of less than 10µA during the detection phase. A programmable current limit prevents high inrush current during power-on. The device features power-mode UVLO with wide hysteresis and long deglitch time to compensate for twisted-pair cable resistive drop and to assure glitch-free transition between detection, classification, and power-on/-off phases.

The MAX5940A/MAX5940C provide an active-high (PGOOD) open-drain output and a fixed UVLO threshold. The MAX5940B/MAX5940D provide both active-high (PGOOD) and active-low (active-low PGOOD) outputs and have an adjustable UVLO threshold with the default value compliant to the 802.3af standard. All devices are designed to work with or without an external diode bridge.

The MAX5940A/MAX5940B/MAX5940C/MAX5940D are available in 8-pin SO packages and are rated over the extended temperature range of -40°C to +85°C.

Data Sheet

Download	Rev 2	(PDF, 248kB)
E-Mail

An evaluation kit is available: MAX5940BEVKIT

Key Features

Fully Integrated IEEE 802.3af-Compliant PD Interface
PD Detection and Programmable Classification Signatures
Less than 10µA Leakage Current Offset During Detection
Integrated MOSFET For Isolation and Inrush Current Limiting
90V Absolute Maximum Rating (MAX5940C/MAX5940D)
Gate Output Allows External Control of the Internal Isolation MOSFET
Programmable Inrush Current Control
Programmable Undervoltage Lockout (MAX5940B/MAX5940D Only)
Wide UVLO Hysteresis Accommodates Twisted-Pair Cable Voltage Drop
PGOOD/Active-Low PGOOD Outputs to Enable Downstream DC-DC Converters
-40°C to +85°C Operating Temperature Range

Applications/Uses

Computer Telephony
IP Phones Security Cameras
Wireless Access Nodes IEEE 802.3af Power Devices

Key Specifications:

Powered Devices

Part Number

IEEE Compliance

R_DS(ON)
(Ω)

PWM

Protection Features

Prog. UVLO

Package/Pins

Smallest Available Pckg.
(mm²)

Oper. Temp.
(°C)

Budgetary Price

PD MOSFET

max w/pins

See Notes

MAX5940

802.3af

0.6

Programmable Inrush Current

Yes

SOIC(N)/8

30.9

-40 to +85

$1.30 @1k

See All Powered Devices (9)

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

Pin Configuration

Application Notes

Application Note 3363		New Ethernet Systems Distribute DC Power with Data
Reference Design 3912		Low-Cost, Complete Power Solution for Powered Devices Includes a 12V Buck Converter

Reliability Reports

Reliability Report:	MAX5940.pdf
Show FIT data for:
Request Reliability Report 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
MAX5940AESA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-5*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5940AESA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5940AESA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5940AESA-T			Active	N.SO;8 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX5940BESA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-5*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5940BESA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5940BESA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5940BESA-T			Active	N.SO;8 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX5940CESA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-5*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5940CESA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-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
MAX5940CESA+T			Active	N.SO;8 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX5940CESA-T			Active	N.SO;8 pin Land Pattern: Not Available	-40°C to +85°C	See data sheet
MAX5940DESA			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-5*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
MAX5940DESA+			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5940DESA+T			Active	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
MAX5940DESA-T			Active	N.SO;8 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.

Similar Products by Function

See All Powered Devices (10 Products)

Similar Products by Application

Digital Video Recorders (DVRs) > Power-Over-Ethernet (PoE)

IP Phones > PD Controller Products

Surveillance DVR 4-Channel > Power-Over-Ethernet

Evaluation Kits

MAX5940BEVKIT

Evaluation Kit for the MAX5940B, MAX5940D

Products with Similar Part Numbers