NCP1234 ONSEMI [ON Semiconductor], NCP1234 Datasheet - Page 9

• Manufacturer Part Number: NCP1234
• Description: Fixed Frequency Current Mode Controller for Flyback Converters
• Manufacturer: ONSEMI [ON Semiconductor]

24
23
22
21
20
19
18
17
16
15
2.20
2.15
2.10
2.05
2.00
1.95
1.90
1.85
1.80
70
69
68
67
66
65
64
63
62
61
60
−50
−50
−50
Figure 9. FB Pin Internal Pull−up Resistor
Figure 11. Oscillator Frequency f
Figure 13. FB Pin Voltage Below Which
−25
−25
−25
Frequency Foldback Starts V
0
0
0
TEMPERATURE (C)
TEMPERATURE (C)
TEMPERATURE (C)
25
25
R
25
FB(up)
TYPICAL PERFORMANCE CHARACTERISTICS
50
50
50
75
75
75
FB(foldS)
OSC
100
100
100
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125
125
125
9
5.30
5.20
5.10
5.00
4.90
4.80
4.70
4.60
1.50
1.45
1.40
1.35
1.30
1.25
1.20
85
84
83
82
81
80
79
78
77
76
75
−50
−50
−50
Frequency Foldback is Complete V
Figure 14. FB Pin Voltage Below Which
Figure 10. FB Pin Open Voltage V
Figure 12. Maximum Duty Cycle D
−25
−25
−25
0
0
0
TEMPERATURE (C)
TEMPERATURE (C)
TEMPERATURE (C)
25
25
25
50
50
50
75
75
75
FB(foldE)
FB(ref)
MAX
100
100
100
125
125
125