Datasheet

NCP1028
http://onsemi.com
5
ELECTRICAL CHARACTERISTICS (continued) (For typical values T
J
= 25°C, for min/max values T
J
= 0°C to +125°C,
Max T
J
= 150°C, V
CC
= 8.0 V, unless otherwise noted.)
Characteristic Pin Symbol Min Typ Max Unit
CURRENT COMPARATOR
Maximum Internal Current Setpoint, Pin 4 Open, T
J
= 25°C,
F
SW
= 65 kHz (Note 3)
- Ipeak_27_CS_
65 k
720 800 880 mA
Final Switch Current with a Primary Slope of 200 mA/ms,
F
SW
= 65 kHz (Note 4)
- Ipeak_27_SW_
65 k
- 820 - mA
Maximum Internal Current Setpoint, Pin 4 Open, T
J
= 25°C,
F
SW
= 100 kHz (Note 3)
- Ipeak_27_CS_
100 k
720 800 880 mA
Final Switch Current with a Primary Slope of 200 mA/ms,
F
SW
= 100 kHz (Note 4)
- Ipeak_27_SW_
100 k
- 820 - mA
Setpoint Decrease for a Pin 7 Injected Current of 40 mA, T
J
= 25°C 7 IOPP - 23 - %
Voltage Level in Pin 7 at which OPP Starts to Operate 7 IOPPtripV - 1.5 - V
Soft-Start Duration - T
SS
- 1.0 - ms
Propagation Delay from Current Detection to Drain OFF State - T
prop
- 100 - ns
Leading Edge Blanking Duration - T
LEB
- 200 - ns
INTERNAL OSCILLATOR
Oscillation Frequency (Note 5)
65 kHz Version, T
J
= 25°C
- f
OSC
58.5 65 71.5
kHz
Oscillation Frequency (Note 5)
100 kHz Version, T
J
= 25°C
- f
OSC
90 100 110
kHz
Frequency Jittering in Percentage of f
OSC
- f
Jitter
- "6.0 - %
Jittering Swing Frequency - 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, T
J
= 25°C (Note 3) 3 IBOhyste 10 11.5 13 mA
Brown-Out Hysteresis Current, T
J
= 0°C to 125°C 3 IBOhyste - 10 - mA
Fault Validation further to Error Flag Assertion - 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 - m s
TEMPERATURE MANAGEMENT
Temperature Shutdown - TSD 160 - - °C
Hysteresis in Shutdown - - - 40 - °C
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.