ltc4270 Linear Technology Corporation, ltc4270 Datasheet - Page 6

• Manufacturer Part Number: ltc4270
• Description: 12-port Poe/poe+/ltpoe++ Pse Controller
• Manufacturer: Linear Technology Corporation

LTC4270/LTC4271
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at T
SYMBOL PARAMETER
XIO
V
V
PSE Timing Characteristics
t
t
t
t
t
t
t
t
t
t
t
t
t
t
6
DET
CLE
CLEON
ME
MEL
PON
TOCL
ED
START
CUT
LIM
MPS
DIS
MSD
OLX
OHX
XIO Digital Output Low
XIO Digital Output High
XIO Digital Input Low Voltage
XIO Digital Input High Voltage
Internal Pull Up to V
Detection Time
Class Event Duration
Class Event Turn On Duration
Mark Event Duration
Last Mark Event Duration
Power On Delay in AUTO Pin Mode
Turn-On Rise Time
Turn-On Ramp Rate
Turn-On Class Transition
Fault Delay
Midspan Mode Detection Backoff
Power Removal Detection Delay
Maximum Current Limit Duration During Port
Start-Up
Maximum Overcurrent Duration After Port Start-
Up
Maximum Current Limit Duty Cycle
Maximum Current Limit Duration After Port Start-
Up – t
Maximum Current Limit Duration After Port Start-
Up – t
Maintain Power Signature (MPS) Pulse Width
Sensitivity
Maintain Power Signature (MPS) Dropout Time
Masked Shut Down Delay
I
Minimum Pulse Width for Masked Shut Down
Minimum Pulse Width for RESET
2
C Watchdog Timer Duration
LIM
LIM
Enabled
as t
CUT
EE
+ 4.3V
A
= 25°C. (Notes 3 & 4)
CONDITIONS
V
V
V
V
XIO0, XIO1
Beginning To End of Detection (Note 7)
(Note 7)
C
(Note 7, Note 11)
Event 2 of 2 or 3 of 3 (Note 7, Note 11)
From End of Valid Detect to Application of
Power to Port (Note 7)
(AGND – V
V
C
C
From I
(Note 7)
R
From Power Removal After t
Detect (Note 7)
(Note 7)
(Note 7)
(Note 7)
t
t
Current Pulse Width to Reset Disconnect
Timer (Note 7, Note 8)
(Note 7, Note 5)
(Note 7)
(Note 7)
(Note 7)
(Note 7)
LIM
LIM
XIOn
XIOn
XIOn
XIOn
PORT
EE
PORT
PORT
PORT
) C
= 1 (Note 7, Note 12)
= 0 (Note 7, Note 12)
The
– V
– V
– V
– V
PORT
= 0.6μF (Note 7)
= 0.15μF (Note 7)
= 0.15μF (Note 7)
CUT
= 15.5kΩ (Note 7)
EE
EE
EE
EE
l
or I
OUT
, I
, I
= 0.15μF (Note 7)
denotes the specifications which apply over the full operating
XIOn
XIOn
LIM
): 10% to 90% of (AGND -
= 5mA
= 100μA
Fault to Next Detect
DIS
to Next
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
320
3.5
3.4
1.0
2.3
1.0
5.8
1.6
1.5
4.5
16
15
52
52
10
52
3
TYP
220
350
8.6
1.1
2.5
1.3
6.3
50
12
22
24
59
59
12
59
2
MAX
380
0.7
0.8
0.1
0.1
2.7
2.5
6.7
3.6
6.5
60
10
66
66
14
66
3
UNITS
42701f
V/μs
ms
ms
ms
ms
ms
ms
ms
ms
ms
ms
ms
ms
ms
kΩ
μs
μs
μs
μs
%
V
V
V
V
s
s
s
s