NCP1282
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
−50 −25 0
25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (°C)
Figure 2. Startup Circuit Inhibit Voltage Threshold
vs. Junction Temperature
12.0
11.5
11.0
VAUX(on)
10.5
10.0
9.5
VAUX(off1)
9.0
8.5
VAUX(off2)
8.0
7.5
7.0
−50 −25 0
25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (°C)
Figure 3. Auxiliary Supply Voltage Thresholds
vs. Junction Temperature
12
11
Vin = 48 V
10
VAUX = Vinhibit + 0.2 V
9
8
7
VAUX = VAUX(on) − 0.2 V
6
5
4
3
2
−50 −25 0
25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (°C)
Figure 4. Startup Current vs. Junction Temperature
10
9
Vin = 48 V
TJ = 25°C
8
7
6
5
4
3
2
1
0
0
2
4
6
8
10
12
VAUX, SUPPLY VOLTAGE (V)
Figure 5. Startup Current vs. Supply Voltage
100
90 VAUX = 12 V
80
70
60
50
40
TJ = −40°C
30
TJ = 25°C
20
10
0
0
TJ = 125°C
50 100 150 200 250 300 350 400 450 500
Vin, INPUT VOLTAGE (V)
Figure 6. Startup Circuit Leakage Current
vs. Input Voltage
http://onsemi.com
8