Datasheet

Idle Detect Class
Mark Class
Mark Class
Between
Ranges
Between
Ranges
Operating
T2P
open-drain
Operating
T2P low
Between
Ranges
UVLO
Rising
UVLO
Falling
UVLO
Rising
UVLO
Falling
TYPE 2 PSE
Hardware Class
Class
TYPE 1 PSE
Hardware Class
Between
Ranges
PoE Startup Sequence
Detect
Mark
Reset
TPS2379
SLVSB98 –MARCH 2012 www.ti.com
ELECTRICAL CHARACTERISTICS (continued)
40 V ≤ V
VDD
≤ 57 V, R
DEN
= 24.9 kΩ, CDB, CLS, GATE, T2P open; –40°C ≤ T
J
≤ 125°C. Positive currents are into pins.
Typical values are at 25°C. All voltages are with respect to V
VSS
(unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Inrush termination Percentage of inrush current 80% 90% 99%
Foldback threshold V
RTN
rising 11 12.3 13.6 V
V
RTN
rising to when current limit changes to inrush current
Foldback deglitch time 500 800 1500 µs
limit
CONVERTER DISABLE (CDB)
Output low voltage I
CDB
= 2 mA, V
RTN
= 2 V, V
DD
: 20 V → 48 V 0.27 0.50 V
Minimum voltage, V
(VDD
V
CDB
= V
DD
, I
CDB
= 1 mA, in inrush 3 V
–RTN)
, for CDB to be valid
Leakage current V
CDB
= 57 V, V
RTN
= 0 V 10 µA
TYPE 2 PSE INDICATION (T2P)
I
T2P
= 2 mA, after 2-event classification and inrush is
V
T2P
Output low voltage 0.26 0.60 V
complete, V
RTN
= 0 V
Leakage current V
T2P
= 57 V, V
RTN
= 0 V 10 µA
UVLO
UVLO rising threshold V
VDD
rising 36.3 38.1 40.0
V
UVLO_R
V
UVLO falling threshold V
VDD
falling 30.5 32.0 33.6
V
UVLO_H
UVLO hysteresis 6.1 V
THERMAL SHUTDOWN
Shutdown T
J
↑ 135 145
°C
Hysteresis 20
V
DD
BIAS CURRENT
Operating current 40 V ≤ V
VDD
≤ 57 V 285 500 µA
Figure 2. PD Class State Diagram
4 Submit Documentation Feedback Copyright © 2012, Texas Instruments Incorporated
Product Folder Link(s) :TPS2379