NCP1249C Datasheet, PDF (13/33 Pages) ON Semiconductor – High-Voltage CurrentMode PWM Controller Featuring Peak Power Excursion

NCP1249C, NCP1249D
TYPICAL CHARACTERISTICS
80.0
250.0
79.8
240.0
79.6
230.0
79.4
220.0
79.2
210.0
79.0
−40 −25 −10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 39. Maximum Duty−cycle, D_max
14.0
200.0
−40 −25 −10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 40. Swing Frequency, f_swing
4.10
13.5
4.05
13.0
4.00
12.5
3.95
12.0
−40 −25 −10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 41. Equivalent ac Resistor from FB to
GND, R_eq
2.00
3.90
−40 −25 −10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 42. FB to Current Set−point Division
Ratio, I_ratio
26.5
1.95
26.0
1.90
25.5
1.85
25.0
1.80
−40 −25 −10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 43. Frequency Foldback Level, V_{fold_FB}
24.5
−40 −25 −10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Figure 44. Transition Frequency Below Which
Skip−cycle Occurs, f_trans
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