Operating Temperature Range ........................ -40NC to +105NC
Storage Temperature Range............................ -65NC to +150NC
Junction Temperature .....................................................+150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
28 TQFN
Junction-to-Ambient Thermal Resistance (q
JA
) ..........29°C/W
Junction-to-Case Thermal Resistance (q
JC
) .................2°C/W
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-lay-
er board. For detailed information on package thermal considerations, refer to
www.maximintegrated.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
AGND
- V
EE
= 32V to 60V, T
A
= -40NC to +105NC, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
- V
EE
= +54V, T
A
= +25NC. Currents are positive when entering the pin and negative otherwise.) (Note 2)
PARAMETER
POWER SUPPLIES
Operating Voltage Range
Supply Current
CURRENT LIMIT
ICUT = 010
ICUT = 011
Class 0, 1, 2, 3 or
ICUT = 000
Class 4 or ICUT = 001
Class 5 if ILIM1 = V
EE
,
ILIM2 = unconnected or
ICUT = 101
Class 5 if ILIM1 =
unconnected, ILIM2 = V
EE
or ICUT = 110
Class 5 if ILIM1 = V
EE
,
ILIM2 = V
EE
or ICUT = 111
Foldback Initial OUT Voltage
Foldback Final OUT Voltage
Minimum Foldback Current-Limit
Threshold
2
SYMBOL
V
AGND
I
EE
V
AGND
- V
EE
CONDITIONS
MIN
32
TYP
MAX
60
UNITS
V
mA
V
OUT
= V
EE
, all logic inputs unconnected,
measured at AGND in power mode
98
185
400
684
807
2.5
4
126
223
420
720
850
155
265
441
756
893
mA
Current Limit
I
LIM
Maximum
I
LOAD
allowed
during
current-limit
conditions,
V
OUT
= 0V
(Note 3)
855
900
945
902
950
27
10
166
998
V
V
mA
Maxim Integrated
V
FLBK_ST
V
FLBK_END
I
TH_FB
V
AGND
- V
OUT
below which the current
limit starts folding back
V
AGND
- V
OUT
below which the current
limit reaches I
TH_FB
V
OUT
= V
AGND
MAX5971B
Single-Port, 40W, IEEE 802.3af/at,
PSE Controller with I2C
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
- V
EE
= 32V to 60V, T
A
= -40NC to +105NC, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
- V
EE
= +54V, T
A
= +25NC. Currents are positive when entering the pin and negative otherwise.) (Note 2)
PARAMETER
OVERCURRENT
ICUT = 010
ICUT = 011
Class 0, 1, 2, 3 or
ICUT = 000
Overcurrent
threshold
allowed for t
P
t
FAULT
, V
OUT
= 0V (Note 3)
Class 4 or ICUT = 001
Class 5 if ILIM1 = V
EE
,
ILIM2 = unconnected or
ICUT = 101
Class 5 if ILIM1 =
unconnected, ILIM2 = V
EE
or ICUT = 110
Class 5 if ILIM1 = V
EE
,
ILIM2 = V
EE
or ICUT = 111
INTERNAL POWER
DMOS On-Resistance
Power-Off OUT Leakage Current
SUPPLY MONITORS
V
EE
Undervoltage Lockout
V
EE
Undervoltage Lockout
Hysteresis
V
EE
Overvoltage Lockout
V
EE
Overvoltage Lockout
Hysteresis
V
EE
Undervoltage
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
OUTPUT MONITOR
OUT Input Current
Idle Pullup Current at OUT
Short to V
EE
Detection Threshold
Short to V
EE
Detection Threshold
Hysteresis
Maxim Integrated
SYMBOL
CONDITIONS
MIN
86
162
351
602
710
TYP
111
196
370
634
748
MAX
136
233
389
666
785
UNITS
Overcurrent Threshold
I
CUT
mA
752
792
832
794
836
878
Measured from
OUT to V
EE
, I
OUT
=
100mA
I
OUT_LEAK
V
EE_UVLO
V
EE_UVLOH
V
EE_OV
V
EE_OVH
V
EE_UV
T
SHD
T
SHDH
I
BOUT
I
DIS
DCN
TH
DCN
HY
T
A
= +25NC
T
A
= +105NC
0.5
0.6
0.9
1.3
10
I
FA
V
V
V
V
V
V
EN
= V
EE
, V
OUT
= V
AGND
V
AGND
- V
EE
, V
AGND
increasing
Port is shutdown if: V
AGND
- V
EE
< V
EE_
UVLO
- V
EE_UVLOH
V
AGND
- V
EE
> V
EE_OV
, V
AGND
increasing
28.5
3
62.5
1
V
EE_UV
event bit sets if: V
AGND
- V
EE
<
V
EE_UV
, V
EE
increasing
Port is shut down and device resets if the
junction temperature exceeds this limit,
temperature increasing
Temperature decreasing
V
OUT
= V
AGND
, probing phases
OUTP discharge current, detection and
classification off, port shutdown,
V
OUTP
= V
AGND
- 2.8V
V
OUT
- V
EE,
V
OUT
decreasing, enabled
during detection
200
1.5
2.0
220
40
+150
20
NC
NC
6
265
2.5
FA
FA
V
mV
3
MAX5971B
Single-Port, 40W, IEEE 802.3af/at,
PSE Controller with I2C
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
- V
EE
= 32V to 60V, T
A
= -40NC to +105NC, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
- V
EE
= +54V, T
A
= +25NC. Currents are positive when entering the pin and negative otherwise.) (Note 2)
PARAMETER
LOAD DISCONNECT
DC Load-Disconnect Threshold
AC Load-Disconnect Threshold
(Note 4)
Triangular Wave Peak-to-Peak
Voltage Amplitude
OSC Pullup/Pulldown Currents
ACD_EN Threshold
I
DC_TH
I
AC_TH
AMP
TRW
I
OSC
V
ACD_EN
Minimum load current allowed before
disconnect (DC disconnect active),
V
OUT
= 0V
Current into DET, for I
DET
< I
AC_TH
the
port powers off (AC disconnect active)
Measured at DET, referred to AGND
Measured at OSC
V
OSC
- V
EE
> V
ACD_EN
to activate AC
disconnect
Time from I
RSENSE
< I
DC_TH
(DC
disconnect active) or I
DET
< I
AC_TH
(AC
disconnect active) to gate shutdown
(Note 5)
V
AGND
- V
DET
during the first detection
phase
V
AGND
- V
DET
during the second detection
phase
V
DET
= V
AGND
during detection, measure
current through DET
If V
AGND
- V
OUT
< V
DCP
after the first
detection phase a short circuit to AGND is
detected.
First point measurement current threshold
for open condition
(Note 6)
Detection rejects lower values
Detection rejects higher values
V
AGND
- V
DET
during classification
V
DET
= V
AGND
, during classification
measure current through DET
Class 0, Class 1
Classification current
thresholds between
classes
Class 1, Class 2
Class 2, Class 3
Class 3, Class 4
Class 4 upper limit
(Note 7)
32
16
65
5.5
13.0
21
31
45
6.5
14.5
23
33
48
20
80
7.5
16.0
25
35
51
mA
19
5
115
3.85
26
270
7.5
130
4
32
330
10
145
4.2
39
380
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
FA
V
FA
mV
Load-Disconnect Timer
DETECTION
Detection Probe Voltage
(First Phase)
Detection Probe Voltage
(Second Phase)
Current-Limit Protection
t
DISC
300
400
ms
V
DPH1
V
DPH2
I
DLIM
3.8
9
1.50
4
9.3
1.75
4.2
9.6
2.00
V
V
mA
Short-Circuit Threshold
V
DCP
1
V
Open-Circuit Threshold
Resistor Detection Window
Resistor Rejection Window
CLASSIFICATION
Classification Probe Voltage
Current-Limit Protection
I
D_OPEN
R
DOK
R
DBAD
20
26.5
15.5
FA
kI
kI
V
CL
I
ClLIM
V
mA
Classification Current Thresholds
I
CL
4
Maxim Integrated
MAX5971B
Single-Port, 40W, IEEE 802.3af/at,
PSE Controller with I2C
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
- V
EE
= 32V to 60V, T
A
= -40NC to +105NC, all voltages are referenced to V
EE
, unless otherwise noted. Typical values are at
V
AGND
- V
EE
= +54V, T
A
= +25NC. Currents are positive when entering the pin and negative otherwise.) (Note 2)
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