NCP1280_05 ONSEMI [ON Semiconductor], NCP1280_05 Datasheet - Page 9

• Manufacturer Part Number: NCP1280_05
• Description: Active Clamp Voltage Mode PWM Controller for Off-Line Applications
• Manufacturer: ONSEMI [ON Semiconductor]

315
310
305
300
295
290
285
100
90
80
70
60
50
19
18
17
16
15
14
13
12
10
11
9
−50
−50
−50
Figure 17. Feedforward Internal Resistance
−25
−25
−25
Figure 19. Maximum Duty Cycle versus
Figure 15. Oscillator Frequency versus
R
R
T
T
T
P
P
versus Junction Temperature
J
J
J
= OPEN, R
= 0 W, R
, JUNCTION TEMPERATURE ( C)
, JUNCTION TEMPERATURE ( C)
, JUNCTION TEMPERATURE ( C)
0
0
0
Junction Temperature
Junction Temperature
25
25
25
MDP
MDP
= OPEN
50
50
50
= OPEN
75
75
75
R
R
100
100
FF
100
T
TYPICAL CHARACTERISTICS
= 101 kW
= 1.0 MW
125
125
125
http://onsemi.com
150
NCP1280
150
150
9
600
500
400
300
200
100
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
90
80
70
60
50
40
30
20
10
0
0
−50
50
0
−25
Figure 20. Soft−Start Charge/Discharge
Figure 18. Maximum Duty Cycle versus
Currents versus Junction Temperature
Figure 16. Oscillator Frequency versus
100
75
DISCHARGE
T
I
T
FF
J
J
= 125 C
, FEEDFORWARD CURRENT (mA)
, JUNCTION TEMPERATURE ( C)
T
CHARGE
0
R
J
150
150
T
= −40 C
Feedforward Current
, TIMING RESISTOR (kW)
Timing Resistor
25
200
225
50
250
300
75
V
V
EA
DCMAX
375
300
100
= 3.0 V
T
DC [ 50%
J
= 25 C
= 0 V
350
450
125
400
150
525
70
65
60
55
50
45
40
35
30