Datasheet

LTC4274A/LTC4274C
7
4274acfc
TYPICAL PERFORMANCE CHARACTERISTICS
Power-On Sequence in
AUTO Pin Mode
Powering Up into a 180μF Load
802.3af Classification in
AUTO Pin Mode
2-Event Classification in
AUTO Pin Mode
Classification Transient Response
to 40mA Load Step
Classification Current Compliance
V
DD
Supply Current vs Voltage V
EE
Supply Current vs Voltage
802.3at I
LIM
Threshold
vs Temperature
100ms/DIV
–70
–60
PORT VOLTAGE (V)
10
0
–10
–20
–30
–40
–50
4274AC G01
V
DD
= 3.3V
V
EE
= –54V
FORCED CURRENT DETECTION
FORCED VOLTAGE
DETECTION
802.3af
CLASSIFICATION
POWER ON
GND
V
EE
5ms/DIV
GND
0mA
4274AC G02
V
EE
V
EE
GATE
VOLTAGE
10V/DIV
PORT
CURRENT
200 mA/DIV
PORT
VOLTAGE
20V/DIV
FOLDBACK
FET ON
425mA
CURRENT LIMIT
LOAD
FULLY
CHARGED
V
DD
= 3.3V
V
EE
= –54V
5ms/DIV
V
EE
–18.4
PORT
VOLTAGE
10V/DIV
GND
4274AC G03
V
DD
= 3.3V
V
EE
= –55V
PD IS CLASS 1
10ms/DIV
V
EE
–17.6
PORT
VOLTAGE
10V/DIV
GND
4274AC G04
V
DD
= 3.3V
V
EE
= –55V
PD IS CLASS 4
1ST CLASS EVENT
2ND CLASS EVENT
50µs/DIV
40mA
0mA
4274AC G05
–20V
PORT
VOLTAGE
1V/DIV
PORT
CURRENT
20mA/DIV
V
DD
= 3.3V
V
EE
= –54V
CLASSIFICATION CURRENT (mA)
–20
CLASSIFICATION VOLTAGE (V)
–18
–16
–14
–12
–10
–8
–6
–4
–2
0
0102030
4274AC G06
40 50 60 70
V
DD
= 3.3V
V
EE
= –54V
T
A
= 25°C
V
DD
SUPPLY VOLTAGE (V)
2.7
0.8
I
DD
SUPPLY CURRENT (mA)
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
2.9 3.1 3.3 3.5
4274AC G07
3.7 3.9 4.1 4.3
85°C
25°C
–40°C
V
EE
SUPPLY VOLTAGE (V)
–60
2.0
I
EE
SUPPLY CURRENT (mA)
2.1
2.2
2.3
2.4
–55 –50 –45 –40
4274AC G08
–35 –30 –25 –20
85°C
25°C
–40°C
TEMPERATURE (°C)
–40
210
V
LIM
(mV)
I
LIM
(mA)
211
213
212
214
215
840
844
852
848
856
860
040
4274AC G09
–80 120
V
DD
= 3.3V
V
EE
= –54V
R
SENSE
= 0.25
REG 48h = C0h