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derating factor
58 Threads found on Derating
Hi I am designed a DC/AC inverter. I already made a prototype 137023 The output voltage is 120Vrms and current of 8 Arms. DC link is 250vdc, Fsw = 25khz. Now I'm designing a new version that is coupled to the electrical network, and with corrections of the first version . The filter is an LC filter with an inductance v
Well, depending on what you know about the grid, and your ability to limit / filter any upside excursions (like is it a small generator driven grid with occasional load-dump spikes, surges, ...) you might define your "380VAC" more conservatively, and this might make a derating exercise pick 1000V rather than 600V FETs. And like that. What you thin
The power is rated at a stated temperature. Read the fine print. Above stated temp the manufacturer provides this derating guidance. A part with a SOA "corner-cut" starting at 125C (case) with a 2C/W derating could be better for you (depending on real case temp that you can hold, by your thermal design) than a part rated at 70C with a -0.5C/W de
I'd go 2X the DC or pulse-peak worst case voltage for a fairly benign environment; more if you have abnormal conditions that expose it to worse. The derating regime (what's acceptable) varies a lot by application / end use and who's criticizing the design and components. In the snubber case realize that the worst case pulse stress may also be aff
Page 5 of this 5-way ERNI connector datasheet (as attached) says that it can carry 17 Amps (Total) at 100degC. However, the temperature derating graph (attached below) for this same connector suggests it can only carry 11.04 Amps over all 5 connector blades at 100degC?which is correct?....11.04 Amps, or 17 Amps?
Very good analysis albbg. Tantalum capacitors normally present low ESR, we can suggest appropriate based on voltage and ripple current rating and derating factors.
There's no specific aging mechanism that can be applied to calculate a lifetime. Running the capacitor with rated current 30K below the maximum full current temperature should give you sufficient margin. The current derating curve suggests that the current limits are calculated for 20K self heating which is quite a lot. There will some thermal s
if you have 80v rated fets that will see 80v in the circuit then that isn't really enough derating. You should pick higher voltage fets, eg100v, but see what the peak transient ring (if any) is across the fets when they switch.
The first of these attempts is the so-called basic OCV analysis. It relies on the fact that best- and worst-case conditions can?t occur at the same time. A single global derating factor is applied to delays to account for the fact that they will be somewhere between best and worst case in reality. This offers some improvement but becomes too cru
Hello, I have a question regarding OCV methodology. I work on a top level that contains a block (that I'm designing also) and I'm looking for the better methodology to apply OCV. At top-level the block is seen as a blak-box (LIB/LEF/GDSII) I use a flat OCV approach (different derating factors for setup/hold data/clock-launch/clock-capture
A lil elaboration of your Answer would be great You didn't get me at all, so sorry! It was a fun answer. Not even the SCNR note led you there? Seems you don't know the meaning of liberty. I'd suggest to look it up in an English dictionary! Anyway, I'd thi
Hi, I need calculate resistor 2.4 ohm let's say from Vishay: I am taking 100W power resistor with overload rating is x10 for 5s. Ambient temperature is 100deg. According graph derating it will be 80%. So effective power dissipation will be 80W. Now I need dissipate 3000W. The pulse duration the resistor withstand is 3000W/(80W*10(factor)*5s~1.
Power in MOSFET is I?R where R=0.85Ω The RdsOn spec for your part. The curve on page 5, using this indicates 2.2°C/W derating of case temp with A vs Tc curve. This is close to my estimate of 1.5~2°C/W. Get a better MOSFET. - - - Updated - - - In my opinion use the continuous ID.
Hysteretic regulators with 1% performance have been around for many years, but Zetex must have used their expertise in very low saturating switches and very fast recovery times to achieve these performance features. I like the thermistor regulation for 75'C derating the output drive. The nearby output Cap of 4.7uF is just there to smoothen the LE
derating value is depend on your library , it also depend on your clock uncertainty. But clock uncertainty and derating , both are different thing. Normally , we put 10% for -early and 20% for -late set_derate_timing -early 0.9 set_derate_timing -late 1.2 Rahul
from Synopsys: Advanced on-chip variation (AOCV) analysis reduces unnecessary pessimism by taking the design methodology and fabrication process variation into account. AOCV determines derating factors based on metrics of path logic depth and the physical distance traversed by a particular path. A longer path that has more gates tends to hav
Skin depth at 50 kHz is 0.3 mm for copper and even higher for bronze etc. contacts. Frequency dependent derating will be negligible. It's definitely a problem for thick conductor bars, e.g. high current connectors or contactors.
Referring to "ampacity" tables and it's derating according to number of circuits would be also my general answer. 1 mm wire diameter refers to about 0,75 mm?. As already mentioned, the standarized rating applies for standard conditions, so you possible arrive at different values for a specific applicat
You want to be very careful in looking at how that rating is specified; there are certain to be assumptions you must meet (case temp, use model (1A forever, 1A 10% of the time). You need to understand your environment - is there a credible fault scenario that could put you at (say) 2A for some period, and you need a 50% derating for confidence? S
Hi, you will need a library which is characterized for 1.0V with this library you can do your synthesis and your sdf simulations. Depending on your position regarding the foudary you may get this library or not. Or maybe your foundary does have a tool for derating an existing library. Maybe you already have some slow/worst case libraries which f
set_operating_condition -analysis_type on_chip_variation to set the analysis to OCV. Now you can set the derates by set_timing_derate -early -cell_delay -net_delay for min derating set_timing_derate -early -cell_delay -net_delay for max derating.
I usually used 5% derating on data and clock, during PnR and STA. that gives more margin. It s good to enable by default the CPPR, to removed the derating impact for the common part of the launch and capture paths. - - - Updated - - - Because for the common path, it could not be worst for the launch and debate for the capt
Typical libraries are also very important. Different libraries have dirrent lookup tables for the delay values and different derating factors too. The skew of a clock could differ and it is not necessary that if it is met in best and worst conditions it will be met in typical too. Thats owing to the skew and derating factors. Hence, it is import
Can anyone help me on how to do a derating analysis for all the tantalum capacitors in an existing circuit? Voltage, current, temperature? where would I look at the values I needed. Thank you.
THis device is an 8 channel high-side switch with separate logic and load grounds (common collector) with Vc 50=Vmax and Ic -500mA an absolute max. and temp derating at 1 watt and assumes ambient is ventilated from self heat. THe emitter output curves indicate an ESR of 1Ω of each transistor. What p/n is your load? and V+ voltage?
Some simple explanation base on my memory & understanding: 1. reconvergence pessimism: when running STA with on-chip-variation, says when checking setup time (whether data travels too slow), tool assumes a rather bad scenario for setup: launching clock & data travels slow & capturing clock travels fast. However, if the launch & capture clocks shar
I have previously used this resistor form in a number of projects. They are disspating the power by surface convection like other ceramic wirewound resistors. The surface gets rather hot. You can read from the derating curve, that they are assuming a surface temperature near to 250 °C. Connection traces of sufficient width should be present to
Is addition of buffer causing setup violation on the exact path violating in hold. Try to upsize the cells in setup path to high drive strength cells. derating could could also be a factor. Check for some hold specific cells being used in the design and convert to normal cell. Hope this helps ---------- Post added at 20:20
derating of current/voltage depends on ambient temperature and pcb material. for further information please refer following link hope this is helpful.
What sort of transformer... a grid distribution transformer, site transformer, etc.? Anyway, in general, large transformers need derating in current due to the lower ability of the less dense air to carry away heat. I've seen a figure of derating by 0.3% for every 100m above 100m altitude. Voltage might also need derating if the (...)
As per my knowledge PCB Layout and thermal analysis and de rating analysis and MTBF calculation all are interlinked .Any one know which tool have all this feature and easy to use.
for derating and MTBF calculation go through the MIL-217F book for manual calculation , regarding free tool i do not know.
Hi friends, I need to calculate the stress parameter (rated specification value, actual stress parameter and derating in %) for my circuit. i have calculated for the resistors, capacitors etc. how to calculate the stress parameter for these ic's? (Micro controller, adc's , dac's opto couplers, max232 and other ic's.) what factors i need to
Hi friends, I need to calculate the stress parameter (rated specification value, actual stress parameter and derating in %) for my circuit. my circuit consists of Micro controller, adc's , dac's opto couplers, max232 and other ic's. how to calculate the stress parameter? what factors i need to consider? somebody please suggest me with th
Its depend on LED specification/charactersics. 20mA should be average DC current allowed and there should be a peak current rating also. If you are controlling the LED with a transistor and PWM at base then Imax*duty should be less than 20mA at 25`C. This average current capabillity will reduce at higher temperature depend on derating curve of LED.
Hi Pavan, Yes you can use two tech libs for OCV simultaneously for min and max delay analysis.. set_min_library is the command for this in PT. You can also set derating factors as well cheers, Thanks for reply. Can you explain to me in detail. If you have any material on this, it would be very useful
Hi i know that we use one lib max then use derating for min. But can we use two libs max and min then use derating on these. Is it possible and is this correct analysis ? Pavan
As mentioned by chuckey, you'll need an LC series circuit ("absorption circuits") for each harmonic to be filtered. For the current in 250 and 350 Hz operation, you have to apply a derating factor to the inductor designed for 80A 50 Hz to consider the core losses. But you would have to know the ratio of core/windings losses and designed magnetizati
What is the derating factor in contex to IC design?
I bet the 500ma is continuous as a rating. The short time frame for the 700 ma you mention is probably fine. Like most semiconductors have a time derating function. However you must take into account how the rest of the device is being used. How much power is is disipating and how hot is is getting. This will drive the derating in the wrong dir
I don't think you have a problem, provided that turnon is at reasonable temperatures and sparse. Note the derating on power, from 100% @ 70C to 0% at 150C. The thermal mass of the resistor ought to keep temperature spike pretty low. You are way below the current limit. Stackpole may have info on pulsed power handling if you dig. If you
For an exact calculation, you would need the SCR's complete thermal data. But you can try a derating of the non-repetitive surge current data. E.g. if the average SCR power dissipation is 50% of the allowed value, considering voltage drop at 500A and actual cooling condidtions, you would keep 50% of the non-repetitive rating. In addition, you shoul
Simply to say, AOCV use different derating ocv factor for different stage. In traditional ocv, one constant derating factor is applied to whole chip. But, from statistical analysis, on-chip-variation will be counteracted with stage increasing. So, AOCV (stage based ocv) is put to reduce over-design.
I guess capacitive coupled differential digital coded transmission with zero dc format like +- pulse sequence. The critical point is have a voltage rise time greater than the maximum common mode voltage or isolation voltage rise or fall time. That is typical specified with a isolation voltage derating at higher isolation voltage frequencies.
the next expression: transformer derating what does it mean...? or what does it involve...? thanks for your help
Hi, I was performing a derating analysis on a diode and as per MIL STD 975, the parameters to be considered are PIV, surge current, forward current and Junction Temperature. The max junction temperature in MIL STD 975 is around 125 deg C for all kinds of diodes. Does that mean for any diode chosen , i need to maintain a junction temperature b
usually when you see 300W capability on a datasheet that it is tested under specific conditions and NO derating considered. no doubt your application is different and you may want more than 5 minutes of reliability... so be mindful on how you select your components. the higher up in power you go the more critical your component selection, layou
After apply derating factor (ocv) to the block design, sdf is written out to capture the derated cell delays. what is the procedure for annotating the block level sdf to top level in design compiler. What is to be done if i have two such blocks for which derating factor (ocv) is applied and I need to annotate these two block sdf's to top-level.
Hi, In the marginless ocv the tool doesn't calcuate the ov margin as per the derating factors for the path, so it will take less run time compared to the normal ocv analysis. Will send you the doc for the same. It may help you. Thanks.. HAK..
i found this answer in synopsys's site. hope it clarifies ur query. Clarification on the Value to Be Specified for slew_derate_from_library Question: In a library that an intellectual property (IP) vendor gave us, the trip points were specified as 30 - 70, with a slew-derating value of 0.5. The vendor tells us that the cells were in fact