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MAX5953, MAX5953A, MAX5953B, MAX5953C, MAX5953D
IEEE 802.3af PD Interface and PWM Controllers with Integrated Power MOSFETs
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Status
All versions are Not Recommended for New Designs.
Description
The MAX5953A/MAX5953B/MAX5953C/MAX5953D
integrate a complete power IC solution for Powered
Devices (PD) in a Power-Over-Ethernet (PoE) system, in
compliance with the IEEE 802.3af standard. The
MAX5953A/MAX5953B/MAX5953C/MAX5953D provide
the PD with a detection signature, a classification signature,
and an integrated isolation switch with programmable
inrush current control. These devices also
integrate a voltage-mode PWM controller with two
power MOSFETs connected in a two-switch voltage-clamped
DC-DC converter configuration.
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 devices
feature power-mode undervoltage lockout (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 MAX5953A/MAX5953C
have an adjustable UVLO threshold with the default
value compliant to the 802.3af standard, while the
MAX5953B/MAX5953D have a lower and fixed UVLO
threshold compatible with some legacy pre-802.3af
power-sourcing equipment (PSE) devices.
The DC-DC converters are operable in either forward or
flyback configurations with a wide input voltage range
from 11V to 76V and up to 15W of output power. The
voltage-clamped power topology enables full recovery
of stored magnetizing and leakage inductive energy for
enhanced efficiency and reliability. When using the
high-side MOSFET, the controller can be configured as
a buck converter. A look-ahead signal for driving secondary-side synchronous rectifiers can be used to
increase efficiency. A wide array of protection features
include UVLO, over-temperature shutdown, and short-circuit
protection with hiccup current limit for enhanced
performance and reliability. Operation up to 500kHz
allows for smaller external magnetics and capacitors.
The MAX5953A/MAX5953B/MAX5953C/MAX5953D are
available in a high-power (2.22W), 7mm x 7mm thermally
enhanced thin QFN package.
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Data Sheet
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Key Features
- Powered Device Interface
- 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
- Gate Output Allows External Control of the Internal Isolation MOSFET
- Programmable Inrush Current Control
- Programmable Undervoltage Lockout (MAX5953A/MAX5953C)
- DC-DC Converter
- Clamped, Two-Switch Power IC for High Efficiency
- Integrated High-Voltage 0.4Ω Power MOSFETs Up to 15W Output Power
- Bias Voltage Regulator with Automatic High-Voltage Supply Turn-Off
- 11V to 76V Wide Input Voltage Range
- Feed-Forward Voltage-Mode Control for Fast Input Transient Rejection
- Programmable Undervoltage Lockout
- Overtemperature Shutdown
- Indefinite Short-Circuit Protection with Programmable Fault Integration
- Integrated Look-Ahead Signal for Secondary-Side Synchronous Rectification
- > 90% Efficiency with Synchronous Rectification
- Up to 500kHz Switching Frequency
- High-Power (2.22W), 7mm x 7mm Thermally Enhanced Lead-Free Thin QFN Package
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Applications/Uses
- Computer Telephony
- IEEE 802.3af Powered Devices
- Internet Appliances
- IP Phones
- Security Cameras
- Wireless Access Nodes
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Diagram
 Typical Operating Circuit
Application Notes
Reliability Reports
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Software/Models
Ordering Information
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Part Number
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Free
Sample |
Buy |
Status
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Package:
TYPE PINS FOOTPRINT
DRAWING CODE/VAR *
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Temp |
RoHS/Lead-Free?
Materials Analysis
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| MAX5953AUTM+
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NRND |
TQFN;48 pin;50.4 mm²
Outline Drawing:21-0144 (PDF)
Land Pattern: 90-0040 (PDF)
Use pkgcode/variation: T4877MN+8*
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0°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX5953AUTM+T
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NRND |
QFN;48 pin
Land Pattern: Not Available
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0°C to +85°C
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See data sheet
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| MAX5953BUTM+
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NRND |
TQFN;48 pin;50.4 mm²
Outline Drawing:21-0144 (PDF)
Land Pattern: 90-0040 (PDF)
Use pkgcode/variation: T4877MN+8*
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0°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX5953BUTM+T
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NRND |
QFN;48 pin
Land Pattern: Not Available
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0°C to +85°C
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See data sheet
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| MAX5953CUTM+
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NRND |
TQFN;48 pin;50.4 mm²
Outline Drawing:21-0144 (PDF)
Land Pattern: 90-0040 (PDF)
Use pkgcode/variation: T4877MN+8*
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0°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX5953CUTM+T
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NRND |
QFN;48 pin
Land Pattern: Not Available
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0°C to +85°C
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See data sheet
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| MAX5953DUTM+
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NRND |
TQFN;48 pin;50.4 mm²
Outline Drawing:21-0144 (PDF)
Land Pattern: 90-0040 (PDF)
Use pkgcode/variation: T4877MN+8*
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0°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX5953DUTM+T
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NRND |
QFN;48 pin
Land Pattern: Not Available
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0°C to +85°C
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See data sheet
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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.
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Information Index
Document Ref.: 19-3945
Rev 1;
2006-07-27
This page last modified: 2009-05-04
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