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