ltc4259a Linear Technology Corporation, ltc4259a Datasheet - Page 5

• Manufacturer Part Number: ltc4259a
• Description: Quad Ieee 802.3af Power Over Ethernet Controller With Ac Disconnect
• Manufacturer: Linear Technology Corporation

CURRENT
20mA/DIV
TYPICAL PERFOR A CE CHARACTERISTICS
VOLTAGE
1V/DIV
PORT
PORT
40mA
VOLTAGE
–18V
0mA
10V/DIV
PORT
Classification Transient Response
to 40mA Load Step
GND
225
200
175
150
125
100
V
75
50
25
EE
0
–48
Current Limit Foldback
Power On Sequence in Auto Mode
PORT 1
V
V
DETECTION
V
V
T
DD
EE
PHASE 1
A
DD
EE
= 25°C
= –48V
= 3.3V
= –48V
–40
= 3.3V
50µs/DIV
–32
DETECTION
V
PHASE 2
W
OUT n
50ms/DIV
CLASSIFICATION
–24
-AGND (V)
V
V
T
U
A
DD
EE
= 25°C
= –48V
= 3.3V
–16
4258 G05
POWER ON
–8
4259 G01
4259 G03
–10
–12
–14
–16
–18
–20
–2
–4
–6
–8
0
0
450
400
350
300
250
200
150
100
50
0
0
Classification Current Compliance
V
V
T
A
DD
EE
PORT VOLTAGE WITH
= 25°C
TYPICAL CMPD3003
= –48V
10
= 3.3V
CLASSIFICATION CURRENT (mA)
20
30
40
500mA/DIV
CURRENT
VOLTAGE
VOLTAGE
PIN VOLTAGE
20V/DIV
10V/DIV
50
DETECT n
PORT
PORT
GATE
60
4258 G06
+14V
GND
0mA
V
V
V
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
EE
EE
EE
0
70
Powering On a 180µF Load
0
INT and SDAOUT Pull Down
Voltage vs Load Current
V
T
A
DD
= 25°C
= 3.3V
FOLDBACK
3.0
2.5
2.0
1.5
1.0
0.5
5
0
–70
LOAD CURRENT (mA)
FET ON
V
Supply Voltage
V
REG 12h = 00h
EE
DD
–60
10
= 3.3V
5ms/DIV
DC Supply Current vs
CURRENT LIMIT
V
–50
425mA
EE
15
SUPPLY VOLTAGE (V)
LTC4259A
–40
V
V
DD
EE
CHARGED
20
FULLY
–30
LOAD
= –48V
= 3.3V
4259 G02
4259 G04
–20
25
–10
4258 G07
4259afb
5
0