Datasheet

LTC4263
5
4263fe
TYPICAL PERFORMANCE CHARACTERISTICS
Powering an IEEE 802.3af PD
Powering a Legacy PD with
220μF Bypass Capacitor
Classifi cation Transient
Response to 40mA Load Step
Overload Restart Delay
Midspan Backoff with Invalid PD Overcurrent Response Time
Response to PD Removal with
AC Disconnect Enabled Rapid Response to 1Ω Short
Rapid Response to
Momentary 50Ω Short
100ms/DIV
V
DD48
V
SS
4263 G01
V
OUT
10V/DIV
POWER
ON
CLASSIFICATION
DETECTION
PHASE 2
DETECTION
PHASE 1
25ms/DIV
V
DD48
V
SS
4263 G02
V
OUT
20V/DIV
I
OUT
200mA/DIV
0mA
400mA
CLASSIFICATION
425mA CURRENT LIMIT
LOAD
FULLY
CHARGED
FOLDBACK
100μs/DIV
V
DD48
– 18V
V
DD48
– 19V
4263 G06
V
OUT
2V/DIV
I
OUT
20mA/DIV
0mA
40mA
V
DD48
– V
SS
= 48V
T
A
= 25°C
500ms/DIV
V
DD48
V
SS
4263 G10
V
OUT
10V/DIV
I
PORT
500mA/
DIV
t
ED
500ms/DIV
V
DD48
4263 G11
V
OUT
2V/DIV
t
DBO
R
PORT
= 15.5kΩ
10ms/DIV
V
DD48
V
SS
4263 G12
V
OUT
20V/DIV
I
OUT
200mA/DIV
0mA
400mA
t
OVLD
LOAD
APPLIED
PORT OFF
50ms/DIV
V
DD48
V
SS
4263 G13
V
OUT
10V/DIV
t
MPDO
PORT OFF
PD REMOVAL
1μs/DIV
V
DD48
V
SS
4263 G14
V
OUT
20V/DIV
I
PORT
20A/
DIV
0A
20A
I
PORT
= CURRENT IN
1Ω RESISTOR APPLIED
TO OUTPUT OF CIRCUIT
ON FRONT PAGE
1Ω SHORT
APPLIED
100μs/DIV
V
DD48
V
SS
4263 G15
V
OUT
20V/DIV
I
PORT
400mA/DIV
0mA
800mA
CURRENT
LIMIT ACTIVE
50Ω SHORT APPLIED
SHORT
REMOVED
FOLDBACK CURRENT LIMIT
I
PORT
= CURRENT IN 50Ω RESISTOR APPLIED
TO OUTPUT OF CIRCUIT ON FRONT PAGE