ncp1377 ON Semiconductor, ncp1377 Datasheet
ncp1377
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ncp1377 Summary of contents
Page 1
... As this happens at low peak current, no audible noise can be heard. For NCP1377, an internal 8.0 ms timer prevents the free-run frequency to exceed 100 kHz (therefore below the 150 kHz CISPR-22 EMI starting limit), while the skip adjustment capability lets the user select the frequency at which the burst foldback takes place ...
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... GND The IC ground 5 Drv Driving pulses 6 V Supplies the High-voltage pin NCP1377, NCP1377B R* NCP1377 Figure 1. Typical Application Schematic The auxiliary FLYBACK signal ensures discontinuous operation and offers a fixed overvoltage detection level of 7 connecting an optocoupler to this pin, the peak current setpoint is adjusted accordingly to the output power demand ...
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... Maximum Voltage on Pin 8 (HV), Pin 6 (V Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. NCP1377, NCP1377B 1.5 us for B Version 4.5 us Delay ...
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... Pin1 Internal Resistance Demag Propagation Delay Timeout After Last Demag Transition Internal Input Capacitance at Vpin 1 = 1.0 V Minimum T (Internal Blanking Delay After T OFF 1. Max value 0°C, please see characterization curves. j NCP1377, NCP1377B = 0°C to +125°C, Max T = 150° Pin Symbol 6 VCC 6 ...
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... Threshold versus Temperature CCON 1.60 1.40 1.20 1.00 0.80 0.60 0.40 - TEMPERATURE (°C) Figure 5. Current Consumption (No Load) versus Temperature 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 - TEMPERATURE (°C) Figure 7. HV Current Source at V versus temperature NCP1377, NCP1377B TYPICAL CHARACTERISTICS 7.90 7.80 7.70 7.60 7.50 7.40 7.30 7.20 -25 75 100 125 Figure 4. V 2.30 2.10 1.90 1.70 1.50 1.30 1.10 75 100 125 -25 0 Figure 6. Current Consumption (1.0 nF Load) 1.10 1.05 1.00 0.95 ...
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... Figure 9. Drive Source Resistance versus Temperature 120 100 - TEMPERATURE (°C) Figure 11. Demagnetization Detection Threshold versus Temperature 10.0 9.5 9.0 8.5 8.0 7.5 7.0 6.5 - TEMPERATURE (°C) Figure 13. Minimum T versus Temperature OFF NCP1377, NCP1377B TYPICAL CHARACTERISTICS 20.0 18.0 16.0 14.0 12.0 10.0 8.0 6.0 4.0 2.0 0.0 75 100 125 -25 0 Figure 10. Drive Sink Resistance versus 7.8 7.6 7.4 7.2 7.0 6.8 6.6 6.4 75 100 125 -25 0 Figure 12 ...
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... NCP1377, NCP1377B • Overvoltage Protection (OVP): By sampling the plateau voltage on the demagnetization winding, the NCP1377 goes into latched fault condition whenever an overvoltage condition is detected. The controller stays fully latched in this position until the Vcc is cycled down to 4.0 V, e.g. when the user unplugs the power supply from the mains outlet and replugs it. • ...
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... NCP1377. To the opposite, in low output power conditions, no more ringing waves are present on the drain and the toggling of the current sense comparator alone initiates a new cycle start ...
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... V -1.0 Figure 21. Core Reset Detection is Done through a Dedicated Auxiliary Winding Monitoring NCP1377, NCP1377B Demag Restart Current Sense and Timeout Restart 5 ms maximum peak current). If anyway a lower skip threshold is needed, care must be taken to select an optocoupler with a Vce(sat) guaranteed to be below the chosen skip level with enough margin ...
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... The overvoltage protection works by sampling the plateau voltage after the turn-off sequence. A 4.5 ms delay NCP1377, NCP1377B for NCP1377 and 1.5 ms for NCP1377B guarantees a clean plateau, providing that the leakage inductance ringing has been fully damped. If this would not be the case, the ) but also avoid false designer should install a small RC damper across the transformer primary inductance connections ...
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... V. When this happens, NCP1377 immediately stops the switching pulses and unbiases all unnecessary logical blocks. The overall consumption drops, while keeping the gate grounded, and the Vcc slowly falls down. As soon as Vcc reaches typically 5 ...
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... Calculating the Vcc Capacitor The Vcc capacitor can be calculated knowing the IC consumption as soon as Vcc reaches Vcc a NCP1377 is used and drives a MOSFET with total gate charge (Qg). The total average current is thus made of Icc1 (1.0 mA) plus the driver current, Fsw 1.8 mA. The total current is therefore 2.8 mA. The DV available to fully startup the circuit (e.g. never reach the 7.5 V UVLO during power on) is 12.5 – ...
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... NCP1377, NCP1377B Figure 29. This plot gathers waveforms captured at three different operating points Upper Plot: Free run, valley switching operation, Pout = Middle Plot: Min Toff clamps the switching frequency and selects the second valley Lowest Plot: The skip slices the second valley pattern and will further expand the burst as Pout goes low ...
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... NCP1377BD1R2G NCP1377P NCP1377PG NCP1377BP NCP1377BPG †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. NCP1377, NCP1377B Vcc (5 V/div) Vgate (5 V/div) in presence of a secondary overload. Package Type SOIC-8 SOIC-8 ...
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... ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/ -T- SEATING PLANE 0.25 (0.010 NCP1377, NCP1377B PACKAGE DIMENSIONS SOIC-8 DR SUFFIX CASE 751-07 ISSUE 0.10 (0.004 SOLDERING FOOTPRINT* 1.52 0.060 7.0 4.0 ...
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... The product described herein (NCP1377), may be covered by one or more of the following U.S. patents: 6,362,067, 6,385,060, 6,385,061, 6,429,709, 6,587,357, 6,633,193. There may be other patents pending. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein ...