NCP1027
ELECTRICAL CHARACTERISTICS (continued) (For typical values TJ = 25°C, for min/max values TJ = 0°C to +125°C,
Max TJ = 150°C, VCC = 8.0 V, unless otherwise noted.)
Characteristic
Pin
Symbol
Min
Typ Max Unit
CURRENT COMPARATOR
Maximum Internal Current Setpoint, Pin 4 Open, TJ = 25°C,
FSW = 65 kHz (Note 3)
Final Switch Current with a Primary Slope of 200 mA/ms,
FSW = 65 kHz (Note 4)
−
Ipeak_27_CS_ 720
800
880
mA
65 k
− Ipeak_27_SW_ −
820
−
mA
65 k
Maximum Internal Current Setpoint, Pin 4 Open, TJ = 25°C,
FSW = 100 kHz (Note 3)
Final Switch Current with a Primary Slope of 200 mA/ms,
FSW = 100 kHz (Note 4)
Setpoint Decrease for a Pin 7 Injected Current of 40 mA, TJ = 25°C
Voltage Level in Pin 7 at which OPP Starts to Operate
−
Ipeak_27_CS_ 720
800
880
mA
100 k
− Ipeak_27_SW_ −
820
−
mA
100 k
7
IOPP
−
23
−
%
7
IOPPtripV
−
1.5
−
V
Soft−Start Duration
Propagation Delay from Current Detection to Drain OFF State
Leading Edge Blanking Duration
INTERNAL OSCILLATOR
−
TSS
−
1.0
−
ms
−
Tprop
−
100
−
ns
−
TLEB
−
200
−
ns
Oscillation Frequency (Note 5)
65 kHz Version, TJ = 25°C
−
fOSC
kHz
58.5
65 71.5
Oscillation Frequency (Note 5)
100 kHz Version, TJ = 25°C
−
fOSC
kHz
90
100 110
Frequency Jittering in Percentage of fOSC
Jittering Swing Frequency
−
fJitter
−
"6.0
−
%
−
fswing
−
300
−
Hz
Maximum Duty Cycle
−
Dmax
74
80
87
%
FEEDBACK SECTION
Internal Pullup Resistor
4
Rupp
−
16
−
kW
Ramp Compensation Level on Pin 1 – Rramp = 100 kW
2
Rlevel
−
2.75
−
V
SKIP CYCLE GENERATION
Internal Skip Mode Level, in Percentage of Maximum Peak Current
−
Iskip
−
25
−
%
PROTECTIONS
Brown−Out Level
3
VBO
510
570
620
mV
Brown−Out Hysteresis Current, TJ = 25°C (Note 3)
Brown−Out Hysteresis Current, TJ = 0°C to 125°C
Fault Validation further to Error Flag Assertion
3
IBOhyste
10
11.5
13
mA
3
IBOhyste
−
10
−
mA
−
TimerON
40
55
−
ms
OFF Phase in Fault Mode
−
TimerOFF
−
440
−
ms
Latching Voltage on Brown−Out Pin
3
Vlatch
3.15
3.5 3.85
V
Latch Input Integrating Filter Time Constant
3
TdelBOL
−
20
−
ms
OVP Integrating Filter Time Constant
−
TdelOVP
−
50
−
ms
VCC Current at which the Switcher Stops Pulsing
TEMPERATURE MANAGEMENT
1
IOVP
6.0
8.5
11
mA
Temperature Shutdown
−
TSD
160
−
−
°C
Hysteresis in Shutdown
−
−
−
40
−
°C
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
3. See characterization curves for full temperature span evolution.
4. The final switch current is: Ipeak_2X_CS + Tprop x Vin / Lp, with Vin the input voltage and Lp the primary inductor in a flyback.
5. Oscillator frequency is measured with disabled jittering.
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