ltc4270 Linear Technology Corporation, ltc4270 Datasheet - Page 8

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

LTC4270/LTC4271
TYPICAL PERFORMANCE CHARACTERISTICS
PORT CURRENT
8
PORT VOLTAGE
GATE VOLTAGE
200mA/DIV
–10
–20
–30
–40
–50
–60
0
20V/DIV
10V/DIV
AGND
802.3af Power On Sequence in
AUTO Pin Mode
VEE
0mA
CLASS 3 PD
VEE = –55V
VEE
VEE
FORCED CURRENT
AGND
Powering Up into a 180μF Load
FET ON
VEE = –54V
FOLDBACK
FORCED VOLTAGE
DETECTION
15.0
12.0
9.0
6.0
3.0
0.0
CLASSIFICATION
50ms/DIV
2.7
DETECTION
POWER ON
V
DD
2.8
Supply Current vs Voltage
5ms/DIV
802.3af
CURRENT LIMIT
2.9
LOAD FULLY CHARGED
V
DD
3.0 3.1 3.2 3.3 3.4
SUPPLY VOLTAGE (V)
425mA
42701 G01
42701 G04
CURRENT
20mA/DIV
VOLTAGE
–10
–20
–30
–40
–50
–60
1V/DIV
3.5
0
PORT
PORT
42701 G07
85°C
25°C
–40
40mA
802.3at Power On Sequence in
AUTO Pin Mode
0mA
–20V
VEE
CLASS 4 PD
3.6
VEE = –55V
AGND
Classification Transient Response
to 40mA Load Step
FORCED CURRENT
V
V
DD
EE
= –54V
= 3.3V
DETECTION
FORCED VOLTAGE
50ms/DIV
CLASSIFICATION
DETECTION
POWER ON
50μs/DIV
9.0
8.5
8.0
7.5
7.0
6.5
6.0
802.3at
–60
V
EE
42701 G02
Supply Current vs Voltage
85°C
25°C
–40
–50
V
42701 G05
EE
SUPPLY VOLTAGE (V)
–40
–10
–15
–20
–25
–10
–12
–14
–16
–18
–20
–5
–2
–4
–6
–8
5
0
0
Power On Sequence with 10V
60Hz Noise
PORT OFF
0
Classification Current Compliance
–30
10
CLASSIFICATION CURRENT (mA)
DETECT WITH 60Hz NOISE
NORMAL DETECT
FORCED CURRENT
AGND
42701 G08
20
DETECTION
–20
50ms/DIV
30
CLASSIFICATION
40
FORCED VOLTAGE
POWER ON
802.3af
50
DETECTION
42701 G03
PP
60
42701 G06
42701f
70