ncp1250 ON Semiconductor, ncp1250 Datasheet
ncp1250
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ncp1250 Summary of contents
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... Current-Mode PWM Controller for Off-line Power Supplies The NCP1250 is a highly integrated PWM controller capable of delivering a rugged and high performance offline power supply in a tiny TSOP−6 package. With a supply range the controller hosts a jittered 65 kHz or 100 kHz switching circuitry operated in peak current mode control ...
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... OPTIONS Controller NCP1250ASN65T1G NCP1250BSN65T1G NCP1250ASN100T1G NCP1250BSN100T1G ORDERING INFORMATION Device Package Marking NCP1250ASN65T1G 25A NCP1250BSN65T1G 252 NCP1250ASN100T1G 25C NCP1250BSN100T1G 25D †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/ ...
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OPP Vlatch OVP gone? VDD Frequency modulation Vfold Vskip VDD RFB / 4.2 FB LEB log ic CC management 600 ns time hiccup constant VDD powe r on reset IpFlag Up counter RST ...
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MAXIMUM RATINGS TABLE Symbol V Power Supply voltage Maximum DRV pin voltage when DRV in H state, transient voltage (Note 1) DRVtran Maximum voltage on low power pins CS, FB and OPP IOPP Maximum injected negative ...
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ELECTRICAL CHARACTERISTICS (For typical values T = 25°C, for min/max values T J Symbol CURRENT COMPARATOR V Maximum internal current setpoint – T Limit2 V Default internal voltage set point for frequency foldback trip point – 45 fold ...
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TEMPERATURE (°C) Figure −50 − TEMPERATURE (°C) Figure 5. ...
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TEMPERATURE (°C) Figure 9. 19.9 19.4 18.9 18.4 17.9 17.4 16.9 16.4 15.9 −50 − TEMPERATURE (°C) Figure 11 ...
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kHz SW 1.5 1 0.5 0 −50 − TEMPERATURE (°C) Figure 15 −50 − TEMPERATURE (°C) Figure 17. 390 340 290 240 ...
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TEMPERATURE (°C) Figure 21. 100 −50 − TEMPERATURE (°C) Figure 23 ...
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TEMPERATURE (°C) Figure 27. 12.9 12.4 11.9 11.4 10.9 10.4 9.9 9.4 8.9 −50 − TEMPERATURE (°C) Figure 29. 1.9 1.8 1.7 1.6 1.5 1.4 1.3 ...
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TEMPERATURE (°C) Figure 33. 390 340 290 240 190 −50 − TEMPERATURE (°C) Figure 35. 160 150 140 130 120 110 100 90 ...
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... Current−mode operation with internal ramp compensation: Implementing peak current mode control at a fixed 65 kHz or 100 kHz, the NCP1250 offers an internal ramp compensation signal that can easily by summed with the sensed current. Sub harmonic oscillations are eliminated via the inclusion of a single resistor in series with the current− ...
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D2 1N4007 12 input mains D4 1N4007 Figure 39. The Startup Resistor Can Be Connected to the Input Mains for Further Power Dissipation Reduction The first step starts with the calculation of the V capacitor which will supply the controller ...
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SCR won’t remain latched. To build a sufficient design margin, we recommend to keep at least 60 mA flowing at the ...
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RoppU This p oin t will be adjusted to reduce the ref at hi line to the desired level. OPP oppL Figure 41. The OPP Circuitry Affects the Maximum Peak Current Set Point by Summing a ...
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Finally, please note that another comparator internally fixes the maximum peak current set point to 0.8 V even if the OPP pin is inadvertently biased above 0 V. Frequency Foldback The reduction of no−load standby power associated with the need ...
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... Figure 45. Inserting a Resistor in Series with the Current Sense Information Brings Ramp Compensation and In the NCP1250 controller, the oscillator ramp features a 2.5 V swing. If the clock operates kHz frequency, then the available oscillator slope corresponds to: vcc vcc vdrv ...
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In our flyback design, let’s assume that our primary is 770 mH, and the SMPS delivers 19 V with inductance ratio of 1:0.25. The off−time primary current slope thus given by: ...
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V. Under 3 mA and neglecting the series diode forward drop, it requires a series resistor of latch VOP OVP OVP OPPL In nominal conditions, ...
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NT C ROPPU 841k OP P ROPPL 2.5k Vlatch Figure 48. The Internal Circuitry Hooked to Pin 3 Can Be Used to Implement Over Temperature Protection (OTP) Back to our 19 V adapter, we have found that the plateau voltage ...
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... ROPPL 2.5k 5 Vlatch Figure 50. A Small RC Filter Avoids the Fast Rising Spikes from Reaching the Protection Pin of the NCP1250 in Presence of Energetic Perturbations Superimposed on the Input Line D2 1N4148 1 OVP OPP Zener diode and the series diode. To prevent an adverse triggering of the Over Voltage Protection circuitry possible to install a small RC filter before the detection network ...
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... Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81−3−5773−3850 http://onsemi.com 22 MILLIMETERS NOM MAX 1.00 1.10 0.06 0.10 0.38 0.50 0.18 0.26 3.00 3.10 2.75 3.00 1.50 1.70 0.95 1.05 0.40 0.60 0.25 BSC 10° − ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative NCP1250/D ...