LTC4274_1 Datasheet, PDF (9/28 Pages) Linear Technology – Single PoE+ PSE Controller High Capacitance Legacy Device Detection

TYPICAL PERFORMANCE CHARACTERISTICS
LTC4274
ADC Noise Histogram
Current Readback in Slow Mode
300
V_SENSEn – V_EE = 110.4mV
250
200
ADC Integral Nonlinearity
Current Readback in Slow Mode
1.0
0.5
ADC Noise Histogram Port
Voltage Readback in Fast Mode
600
AGND – V_OUTn = 48.3V
500
400
150
0
300
100
200
–0.5
50
100
0
6139 6141 6143 6145 6147
ADC OUTPUT
4274 G17
–1.0
0 50 100 150 200 250 300 350 400 450 500
CURRENT SENSE RESISTOR INPUT VOLTAGE (mV)
4274 G18
0
260
261 262 263 264
ADC OUTPUT
265
4274 G19
ADC Integral Nonlinearity
Voltage Readback in Fast Mode
1.0
0.5
ADC Noise Histogram Port
Voltage Readback in Slow Mode
600
AGND – V_OUTn = 48.3V
500
400
ADC Integral Nonlinearity
Voltage Readback in Slow Mode
1.0
0.5
0
300
0
200
–0.5
–0.5
100
–1.0
0
10 20 30 40 50 60
PORT VOLTAGE (V)
4274 G20
0
8532
8533 8534 8535
ADC OUTPUT
8536
4274 G21
–1.0
0
10 20 30 40 50 60
PORT VOLTAGE (V)
4274 G22
INT and SDAOUT Pull Down Voltage
vs Load Current
3
2.5
2
1.5
1
0.5
0
0 5 10 15 20 25 30 35 40
LOAD CURRENT (mA)
4274 G23
MOSFET Gate Drive With Fast
Pull Down
GND
PORT
VOLTAGE
20V/DIV
V_EE
GATE
VOLTAGE
10V/DIV V_EE
50Ω
FAULT
PORT
APPLIED
CURRENT
500mA/DIV 0mA
V_DD = 3.3V
V_EE = –54V
FAST PULL DOWN
CURRENT LIMIT
50Ω FAULT REMOVED
100μs/DIV
4274 G24
4274fa
9