Manual
_______________________________________________________________________________________ 3
MAX5971B
Single-Port, 40W, IEEE 802.3af/at,
PSE Controller with I
2
C
ELECTRICAL CHARACTERISTICS (continued)
(V
AGND
- V
EE
= 32V to 60V, T
A
= -40NC to +85NC, 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 SYMBOL CONDITIONS MIN TYP MAX UNITS
OVERCURRENT
Overcurrent Threshold I
CUT
Overcurrent
threshold
allowed for t P
t
FAULT
, V
OUT
= 0V (Note 3)
Class 0, 1, 2, 3 or ICUT
= 000
351 370 389
mA
Class 4 or ICUT = 001 602 634 666
Class 5 if ILIM1 = V
EE
,
ILIM2 = unconnected or
ICUT = 101
710 748 785
Class 5 if ILIM1 =
unconnected, ILIM2 = V
EE
or ICUT = 110
752 792 832
Class 5 if ILIM1 = V
EE
,
ILIM2 = V
EE
or ICUT = 111
794 836 878
INTERNAL POWER
DMOS On-Resistance
Measured from
OUT to V
EE
, I
OUT
=
100mA
T
A
= +25NC
0.5 0.9
I
T
A
= +85NC
0.6 1.3
Power-Off OUT Leakage Current I
OUT_LEAK
V
EN
= V
EE
, V
OUT
= V
AGND
10
FA
SUPPLY MONITORS
V
EE
Undervoltage Lockout V
EE_UVLO
V
AGND
- V
EE
, V
AGND
increasing 28.5 V
V
EE
Undervoltage Lockout
Hysteresis
V
EE_UVLOH
Port is shutdown if: V
AGND
- V
EE
< V
EE_
UVLO
- V
EE_UVLOH
3 V
V
EE
Overvoltage Lockout V
EE_OV
V
AGND
- V
EE
> V
EE_OV
, V
AGND
increasing 62.5 V
V
EE
Overvoltage Lockout
Hysteresis
V
EE_OVH
1 V
V
EE
Undervoltage V
EE_UV
V
EE_UV
event bit sets if: V
AGND
- V
EE
<
V
EE_UV
, V
EE
increasing
40 V
Thermal Shutdown Threshold T
SHD
Port is shut down and device resets if the
junction temperature exceeds this limit,
temperature increasing
150
NC
Thermal Shutdown Hysteresis T
SHDH
Temperature decreasing 20
NC
OUTPUT MONITOR
OUT Input Current I
BOUT
V
OUT
= V
AGND
, probing phases 6
FA
Idle Pullup Current at OUT I
DIS
OUTP discharge current, detection and
classification off, port shutdown,
V
OUTP
= V
AGND
- 2.8V
200 265
FA
Short to V
EE
Detection Threshold DCN
TH
V
OUT
- V
EE,
V
OUT
decreasing, enabled
during detection
1.5 2.0 2.5 V
Short to V
EE
Detection Threshold
Hysteresis
DCN
HY
220 mV