MAX5953B Datasheet PDF - Maxim Integrated Products

www.Datasheet-PDF.com

MAX5953B
Maxim Integrated Products

Part Number MAX5953B
Description (MAX5953x) IEEE 802.3af PD Interface and PWM Controllers
Page 27 Pages


MAX5953B datasheet pdf
View PDF for PC
MAX5953B pdf
View PDF for Mobile


No Preview Available !

www.DataSheet4U.com
19-3945; Rev 0; 1/06
IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
General 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 sig-
nature, and an integrated isolation switch with program-
mable 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 pre-
vents 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 sec-
ondary-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 ther-
mally enhanced thin QFN package.
Applications
IEEE 802.3af Powered
Devices
IP Phones
Wireless Access Nodes
Internet Appliances
Security Cameras
Computer Telephony
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 0.4Power 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
Ordering Information
PART
PIN-PACKAGE
PKG CODE
MAX5953AUTM+*
48 TQFN
T4877-6
MAX5953BUTM+
48 TQFN
T4877-6
MAX5953CUTM+*
48 TQFN
T4877-6
MAX5953DUTM+*
48 TQFN
T4877-6
Operating junction temperature range is 0°C to +125°C.
+Denotes lead-free package.
*Future product—contact factory for availability.
Pin Configuration and Typical Operating Circuit appear at
end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.



No Preview Available !

www.DataSheet4U.com
IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
ABSOLUTE MAXIMUM RATINGS
V+ to VEE ................................................................-0.3V to +90V
OUT, PGOOD, PGOOD to VEE.....................-0.3V to (V+ + 0.3V)
RCLASS, GATE to VEE ...........................................-0.3V to +12V
UVLO to VEE ............................................................ -0.3V to +8V
PGOOD to OUT ........................................... -0.3V to (V+ + 0.3V)
HVIN, INBIAS, DRNH, XFRMRH,
XFRMRL to GND.................................................-0.3V to +80V
BST to GND ........................................................... -0.3V to +95V
BST to XFRMRH .................................................... -0.3V to +12V
PGND to GND .......................................................-0.3V to +0.3V
DCUVLO, RAMP, CSS, OPTO, FLTINT, RCFF,
RTCT to GND..................................................... -0.3V to +12V
SRC, CS to GND...................................................... -0.3V to +6V
REGOUT, DRVIN to GND .......................................-0.3V to +12V
REGOUT to HVIN .................................................. -80V to +0.3V
REGOUT to INBIAS ............................................... -80V to +0.3V
PPWM to GND....................................-0.3V to (VREGOUT + 0.3V)
*As per JEDEC 51 standard.
Maximum Input/Output Current (Continuous)
OUT to VEE....................................................................500mA
V+, RCLASS to VEE.........................................................70mA
UVLO, PGOOD, PGOOD to VEE .....................................20mA
GATE to VEE....................................................................80mA
REGOUT to GND ............................................................50mA
DRNH, XFRMRH, XFRMRL, SRC to GND (Average),
TJ = +125°C..................................................................0.9A
PPWM to GND ..............................................................±20mA
Continuous Power Dissipation* (TA = +70°C)
48-Pin TQFN 7mm X 7mm
(derate 27.8mW/°C above +70°C) .............................2222mW
θJA ................................................................................36°C/W
Operating Ambient Temperature Range ................0°C to +85°C
Operating Junction Temperature Range ..............0°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VIN = (V+ - VEE) = 48V, GATE = PGOOD = PGOOD = unconnected, GND = OUT, HVIN = V+, UVLO = VEE, TJ = 0°C to +125°C, unless
otherwise noted. Typical values are at TJ = +25°C. All voltages are referenced to VEE, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
POWERED DEVICE (PD) INTERFACE
DETECTION MODE
Input Offset Current
IOFFSET
Effective Differential Input
Resistance (Note 3)
dR
CONDITIONS
VIN = 1.4V to 10.1V (Note 2)
VIN = 1.4V, up to 10.1V with 1V step
MIN TYP MAX UNITS
10 µA
550 k
CLASSIFICATION MODE
Classification Current Turn-Off
Threshold
VTH,CLASS VIN rising (Note 4)
20.8 21.8 22.5
V
Classification Current
POWER MODE
Operating Supply Voltage
Operating Supply Current
Default Power Turn-On Voltage
Default Power Turn-Off Voltage
ICLASS
VIN = 12.6V
to 20V,
RDISC =
25.5k
(Notes 5, 6)
Class 0, RRCLASS = 10k
Class 1, RRCLASS = 732
Class 2, RRCLASS = 392
Class 3, RRCLASS = 255
Class 4, RRCLASS = 178
0
9.17
17.29
26.45
36.6
2
11.83
19.71
29.55
41.4
VIN
IIN
VUVLO, ON
VUVLO,OFF
VIN = (V+ - VEE)
Measure at V+, not including RDISC,
GATE = VEE, HVIN = GND = OUT
VIN
increasing
MAX5953A/MAX5953C
MAX5953B/MAX5953D
VIN decreasing, MAX5953A/MAX5953C
67
0.4 1
37.4 38.6 40.2
34.3 35.4 36.9
30
mA
V
mA
V
V
2 _______________________________________________________________________________________



No Preview Available !

www.DataSheet4U.com
IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
ELECTRICAL CHARACTERISTICS (continued)
(VIN = (V+ - VEE) = 48V, GATE = PGOOD = PGOOD = unconnected, GND = OUT, HVIN = V+, UVLO = VEE, TJ = 0°C to +125°C, unless
otherwise noted. Typical values are at TJ = +25°C. All voltages are referenced to VEE, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX UNITS
Default Power Turn-On/Off
Hysteresis Voltage
MAX5953A/MAX5953C
VHYST,UVLO MAX5953B/MAX5953D
7.1
4
V
External UVLO Programming
Range
VIN,EX MAX5953A/MAX5953C only (Note 7)
12
67 V
UVLO External Reference
Voltage
VREF,UVLO VUVLO increasing
2.400 2.460 2.522
V
UVLO External Reference
Voltage Hysteresis
UVLO Bias Current
UVLO Input Ground-Sense
Threshold
VHYST,UVLO Ratio to VREF, UVLO
IIN,UVLO VUVLO = 2.460V
VTH,G,UVLO (Note 8)
19.2 20 20.9
%
-1.5
+1.5
µA
50 440 mV
UVLO Input Ground-Sense Glitch
Rejection
7 µs
Power Turn-Off Voltage,
Undervoltage Lockout Deglitch
Time
tOFF_DLY VIN, VUVLO falling (Note 9)
0.32
ms
Isolation Switch n-Channel
MOSFET On-Resistance
Isolation Switch n-Channel
MOSFET Off-Threshold Voltage
RON,ISO
VGSTH
Output current = 300mA, VGATE = 5.6V,
measured between OUT and VEE
VGATE - VEE, OUT = V+,
output current < 1µA
0.6 1.5
0.5
V
GATE Pulldown Switch
Resistance
GATE Charging Current
GATE High Voltage
PGOOD Assertion VOUT
Threshold (Note 10)
PGOOD, PGOOD Assertion
VGATE Threshold
PGOOD, PGOOD Output Low
Voltage
PGOOD Leakage Current
PGOOD Leakage Current
RG Power-off mode, VIN = +12V
IGATE
VGATE
VOUTEN
VGSEN
VGATE = 2V
IGATE = 1µA
VOUT - VEE decreasing, VGATE = 5.75V
Hysteresis
VGATE - VEE increasing
Hysteresis
VOL,PGOOD ISINK = 2mA, VOUT (V+ - 5V) (Note 11)
GATE = high, V+ - VOUT = 67V (Note 11)
GATE = VEE, PGOOD - VEE = 67V
(Note 11)
4.5
5.59
1.16
4.62
38
10
5.76
1.23
70
4.76
80
80
16.5
5.93
1.31
4.91
0.2
1
1
µA
V
V
mV
V
mV
V
µA
µA
_______________________________________________________________________________________ 3



No Preview Available !

www.DataSheet4U.com
IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
ELECTRICAL CHARACTERISTICS (DC-DC Controller)
(All voltages referenced to GND, unless otherwise noted. VHVIN = +48V, CINBIAS = 1µF, CREGOUT = 2.2µF, RRTCT = 25k, CRTCT =
100pF, CBST = 0.22µF, VCSS = VCS = 0V, VRAMP = VDCUVLO = 3V, TJ = 0°C to +125°C, unless otherwise noted. Typical values are at
TJ = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
Input Supply Range
OSCILLATOR (RTCT)
PWM Frequency
Maximum PWM Duty Cycle
Maximum RTCT Frequency
RTCT Peak Trip Level
RTCT Valley Trip Level
RTCT Input Bias Current
RTCT Discharge MOSFET
RDS(ON)
RTCT Discharge Pulse Width
LOOK-AHEAD LOGIC (PPWM)
SYMBOL
VHVIN
fS
DMAX
fRTCTMAX
VTH,RTCT
VTL,RTCT
IIN,RTCT
RDIS,RTCT
CONDITIONS
(Note 12)
Sinking 50mA
MIN TYP MAX UNITS
11 76 V
250
47
1
0.51 x VREGOUT
1
±1
35 85
50
kHz
%
MHz
V
V
µA
ns
PPWM to Output Propagation
Delay
tPPWM
VPPWM rising to VXFRMRL falling
110 ns
PPWM Output High
VOH,PPWM
PPWM Output Low
VOL,PPWM
PWM COMPARATOR (OPTO, RAMP, RCFF)
Common-Mode Input Range
Input Offset Voltage
VCM_PWM
Input Bias Current
Sourcing 2mA
Sinking 2mA
7.0 11.0 V
0.2 V
0 5.5 V
10 mV
-2 +2 µA
RAMP to XFRMRL Propagation
Delay
Minimum OPTO Voltage
Minimum RCFF Voltage
REGOUT LDO (REGOUT)
tCOMPARATOR
From VRAMP (50mV overdrive) rising to
VXFRMRL rising
VCSS = 0V, OPTO sinking 2mA
RCFF sinking 2mA
100 ns
1.47 V
2.18 V
REGOUT Voltage Set Point
REGOUT Load Regulation
REGOUT Dropout Voltage
REGOUT Undervoltage
Lockout Threshold
VREGOUT
INBIAS unconnected,
VHVIN = 11V to 76V
VINBIAS = VHVIN = 11V to 76V
INBIAS unconnected, VHVIN = 15V,
IREGOUT = 0 to 30mA
VINBIAS = VHVIN = 15V,
IREGOUT = 0 to 30mA
INBIAS unconnected, IREGOUT = 30mA
VINBIAS = VHVIN, IREGOUT = 30mA
REGOUT rising
8.3 8.75 9.2
9.5 10.6 11.0
0.25
0.25
1.25
1.25
6.6 7.0 7.4
V
V
V
V
REGOUT Undervoltage
Lockout Threshold Hysteresis
REGOUT falling
0.7 V
4 _______________________________________________________________________________________



MAX5953B datasheet pdf
Download PDF
MAX5953B pdf
View PDF for Mobile


Related : Start with MAX5953 Part Numbers by
MAX5953A (MAX5953x) IEEE 802.3af PD Interface and PWM Controllers MAX5953A
Maxim Integrated Products
MAX5953A pdf
MAX5953B (MAX5953x) IEEE 802.3af PD Interface and PWM Controllers MAX5953B
Maxim Integrated Products
MAX5953B pdf
MAX5953C (MAX5953x) IEEE 802.3af PD Interface and PWM Controllers MAX5953C
Maxim Integrated Products
MAX5953C pdf
MAX5953D (MAX5953x) IEEE 802.3af PD Interface and PWM Controllers MAX5953D
Maxim Integrated Products
MAX5953D pdf

Index :   0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   

This is a individually operated, non profit site. If this site is good enough to show, please introduce this site to others.
Since 2010   ::   HOME   ::   Privacy Policy + Contact