Info!! What Is The Semi F47 Business Sag Spec All About?

We accept all seen lights dim at habitation or at function in addition to this is an indication that the air conditioning describe of piece of employment voltage has been reduced or sagged. Although an occasional dimming of lights tin last tolerated, when it comes to manufactory automation equipment, describe of piece of employment sag tin last the origin of a production shutdown, resulting inwards meaning revenue losses. Since the production of semiconductors, including microprocessors, is a really precise in addition to expensive process, dorsum inwards 1999 the Semiconductor Equipment in addition to Materials Institute (SEMI), established standards relative to air conditioning describe of piece of employment sag immunity. This specification is called the SEMI F47 Voltage Sag Immunity Standard in addition to has been revised periodically. Because many other manufactory automation processes are as critical, some of these production products ask to comply alongside the SEMI F47 measure as well.


Basically, this measure requires that the AC-DC ability render that is used inwards semiconductor production, or inwards other manufactory automation equipment, proceed to provide the required output voltage in addition to current, fifty-fifty if the input voltage dips below its specified limits. As tin last seen inwards the nautical chart below, inwards the bluish area, the basic specs require that the ability render perform usually fifty-fifty if the input voltage sags downward to 50% of its nominal voltage for upwards to 200 ms, or sags to 70% for upwards to 500 ms, in addition to sags to 80% for upwards to i second. Since this sag per centum refers to the nominal describe of piece of employment voltage, this agency for illustration that alongside a nominal 220VAC input, the air conditioning voltage tin sag downward to 50% or 110VAC for upwards to 200 ms, downward to 70% or 154VAC for 500 ms, in addition to downward to 80% or 176VAC for upwards to i second.


There are additional sag ride-through “recommendations” inside the latest version of the standard, which is the SEMI F47-0706 (these recommendations are non requirements) that includes functioning of the ability render alongside 0% input ability (no power) for upwards to xx ms. This recommendation tin last accommodated past times insuring the selected ability render has a “hold-up time” specification of xx ms or longer. Other newly recommended thresholds inside the SEMI F47-0706 include sags of 80% for 10 seconds, in addition to continuous sags of 90%. Most ability supplies that consider the previous versions of this standard, the SEMI F47-0200, in addition to accept a hold-up spec of xx ms or greater, should last able to consider the novel recommendations (not requirements) as well.

The simplest in addition to lowest toll method of complying alongside the SEMI F47 measure is to role a ability render alongside a universal input, such as ninety to 264VAC, in addition to operate it from a 220VAC or higher describe of piece of employment input. In this way you lot automatically consider in addition to move on the measure since this type of ability render tin operate downward to 90VAC (even lower than the 50% describe of piece of employment sag spec of 110VAC). Note that this method does apply to auto-strap ability supplies.

Another way of coming together the SEMI F47 is to depict less ability than the render tin usually provide (de-rate the supply). If you lot create this, ever banking concern friction match alongside the manufacturer to confirm that your reduced charge volition let the render to fully consider the SEMI F47 standard. This may require extra testing to confirm compliance, either past times the ability render manufacturer or the end-product OEM. Alternatively, the ability render manufacturer may last able to alter the render to consider the SEMI F47 standard.

Some manufactory automation equipment require the role of SEMI F47 “certified” ability supplies, which agency the supplies were tested past times an exterior agency or laboratory in addition to found to fully comply alongside the measure (similar to UL certification). If this is a requirement, ever await for supplies that accept existing certifications from a reliable manufacture, because the toll of getting this type of certification tin amount to $2,000 or more. There is a granddad clause inwards the updated standards that provides for equipment that was tested or certified nether the previous versions of the measure to non require re-testing or re-certification.

Many industrial-type ability supplies are designed and/or certified to consider the SEMI F47. These supplies may last a fighting to a greater extent than expensive, simply it volition last the lowest toll solution, particularly if you lot compare it to the toll of adding an external constant voltage transformer or UPS to the input of the ability supply.

Power render manufacturers such as TDK-Lambda offering supplies that are SEMI F47 certified in addition to supplies that operate alongside a broad universal input of ninety to 264VAC. In addition, modified supplies tin last provided that consider this in addition to other prevailing ability render specifications.