Datasheet

LTC4270/LTC4271
6
42701fc
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
XIO
V
OLX
XIO Digital Output Low V
XIOn
– V
EE
, I
XIOn
= 5mA
l
0.7 V
V
OHX
XIO Digital Output High V
XIOn
– V
EE
, I
XIOn
= 100µA
l
3.5 V
XIO Digital Input Low Voltage V
XIOn
– V
EE
l
0.8 V
XIO Digital Input High Voltage V
XIOn
– V
EE
l
3.4 V
Internal Pull Up to CAP2 XIO0, XIO1 50 kΩ
PSE Timing Characteristics
t
DET
Detection Time Beginning To End of Detection (Note 7) 220 ms
t
CLE
Class Event Duration (Note 7) 12 ms
t
CLEON
Class Event Turn On Duration C
PORT
= 0.6µF (Note 7)
l
0.1 ms
t
ME
Mark Event Duration (Note 7, Note 11) 8.6 ms
t
MEL
Last Mark Event Duration (Note 7, Note 11)
l
16 22 ms
t
PON
Power On Delay in AUTO Pin Mode From End of Valid Detect to Application of Power to Port
(Note 7)
l
60 ms
Turn-On Rise Time (AGND – V
OUT
): 10% to 90% of (AGND - V
EE
) C
PORT
=
0.15µF (Note 7)
l
15 24 µs
Turn-On Ramp Rate C
PORT
= 0.15µF (Note 7)
l
10 V/µs
t
TOCL
Turn-On Class Transition C
PORT
= 0.15µF (Note 7)
l
0.1 ms
t
ED
Fault Delay From I
CUT
or I
LIM
Fault to Next Detect
(Note 7)
l
1.0 1.1 s
Midspan Mode Detection Backoff R
PORT
= 15.5kΩ (Note 7)
l
2.3 2.5 2.7 s
Power Removal Detection Delay From Power Removal After t
DIS
to Next Detect (Note 7)
l
1.0 1.3 2.5 s
t
START
Maximum Current Limit Duration
During Port
Start-Up
(Note 7)
l
52 59 66 ms
t
CUT
Maximum Overcurrent Duration
After Port Start-Up
(Note 7)
l
52 59 66 ms
Maximum Overcurrent Duty Cycle (Note 7)
l
5.8 6.3 6.7 %
t
LIM
Maximum Current Limit Duration
After Port Start-Up – t
LIM
Enabled
t
LIM
= 1 (Note 7, Note 12)
l
10 12 14 ms
Maximum Current Limit Duration
After Port Start-Up – t
LIM
as t
CUT
t
LIM
= 0 (Note 7, Note 12)
l
52 59 66 ms
t
MPS
Maintain Power Signature (MPS)
Pulse Width Sensitivity
Current Pulse Width to Reset Disconnect Timer (Note 7,
Note 8)
l
1.6 3.6 ms
t
DIS
Maintain Power Signature (MPS)
Dropout Time
(Note 7, Note 5)
l
320 350 380 ms
t
MSD
Masked Shut Down Delay (Note 7) 6.5 µs
I
2
C Watchdog Timer Duration (Note 7)
l
1.5 2 3 s
Minimum Pulse Width for Masked
Shut Down
(Note 7)
l
3 µs
Minimum Pulse Width for RESET (Note 7)
l
4.5 µs
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. AGND – V
EE
= 54V and V
DD
– DGND = 3.3V unless otherwise noted.
(Notes 3 & 4)