NCP1070, NCP1071, NCP1072, NCP1075, NCP1076, NCP1077
ELECTRICAL CHARACTERISTICS
(For typical values TJ = 25°C, for min/max values TJ = −40°C to +125°C, VCC = 8 V unless otherwise noted)
Symbol
Rating
Pin
Min
Typ
Max
Unit
CURRENT COMPARATOR
IIPKSW
Final switch current with a primary slope of 200 mA/ms,
FSW =100 kHz (Note 3)
NCP1070
NCP1071
NCP1072
NCP1075
NCP1076
NCP1077
mA
−
309
−
−
415
−
−
293
−
−
500
−
−
706
−
−
845
−
IIPKSW
Final switch current with a primary slope of 200 mA/ms,
FSW =130 kHz
NCP1070 (Note 4)
NCP1071 (Note 4)
NCP1072 (Note 4)
NCP1075
NCP1076 (Note 4)
NCP1077 (Note 4)
mA
−
303
−
−
407
−
−
291
−
−
493
−
−
684
−
−
814
−
TSS
Soft−start duration (guaranteed by design)
Tprop
Propagation delay from current detection to drain OFF state
INTERNAL OSCILLATOR
−
−
1
−
ms
−
−
100
−
ns
fOSC
fOSC
fOSC
fjitter
fswing
Dmax
Oscillation frequency, 65 kHz version, Tj = 25°C (Note 5)
Oscillation frequency, 100 kHz version, Tj = 25°C (Note 5)
Oscillation frequency, 130 kHz version, Tj = 25°C (Note 4 et 5)
Frequency jittering in percentage of fOSC
Jittering swing frequency
Maximum duty−cycle
NCP1070/71/72/75
NCP1076/77
−
59
65
71
kHz
−
90
100
110
kHz
−
117
130
143
kHz
−
−
±6
−
%
−
−
300
−
Hz
%
−
62
68
72
−
65
69
73
FEEDBACK SECTION
IFBfault
IFB100%
IFBFreeze
VFB(REF)
FB current for which Fault is detected
FB current for which internal current set−point is 100% (IIPK(0))
FB current for which internal current set−point is IFreeze
Equivalent pull−up voltage in linear regulation range
(Guaranteed by design)
4
−35
mA
4
−44
mA
4
−
−90
−
mA
4
3.3
V
RFB(up) Equivalent feedback resistor in linear regulation range
(Guaranteed by design)
4
19.5
kW
FREQUENCY FOLDBACK & SKIP
IFBfold
IFBfold(end)
Fmin
IFBskip
IFreeze
Start of frequency foldback feedback level
End of frequency foldback feedback level, Fsw = Fmin
The frequency below which skip−cycle occurs
The feedback level to enter skip mode
Internal minimum current setpoint (IFB = IFBFreeze)
NCP1070
NCP1071
NCP1072
NCP1075
NCP1076
NCP1077
4
−
−68
−
mA
4
−
−100
−
mA
−
21
25
29
kHz
4
−
−120
−
mA
mA
−
−
88
−
−
123
−
−
88
−
−
168
−
−
228
−
−
280
−
3. The final switch current is: IIPK(0) / (Vin/LP + Sa) x Vin/LP + Vin/LP x tprop, with Sa the built−in slope compensation, Vin the input voltage, LP
the primary inductor in a flyback, and tprop the propagation delay.
4. NCP1070/71/72/76/77 130 kHz on demand only.
5. Oscillator frequency is measured with disabled jittering.
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