------Question for ECS-2520Q-33-480-BP-TR Please Put your question below------
The specs show ECS-2520Q DP -40 to 105C at 30ppm and BS -40 to 125 at 50ppm, but Digikey and Mouser both have BP, not BS parts available. The D indicates 30ppm and B 50ppm while S is the higher temperature range on the spec. According to that, there should be no such part as 480-BP. The DP part number is correct, so I’m guessing the -BP is really -BS and 125C at 50ppm. Am I right?
Usually in an order code, you can combine any number of letters and it would still be valid. In other words, you can have a 50ppm part and still have a temperature range of -40 to 105C. There is a possibility Mouser may have it recorded wrong. The datasheet does say that BP means 50ppm at -40 to 105C.
Hi Kalelb,
On these oscillators, the frequency instability and temperature limit are not independent. At high temperatures, they both rise together. So, if one part has 30ppm at 105C, one expects to see another variant or even the same part to sustain up to 50ppm at 125C.
In any case, the spec sheet called out ONLY two variants in the CONDITIONS (of testing) table: the -DP and the -BC. But there are not any -BC parts available, only -DP and -BP with specs of 30ppm at 105C and 50ppm at 105C. Not impossible, but stupid & redundant if the CONDITIONS table is correct. Furthermore, the -BC part is the part we were looking for and we hoped the part number of -BP was mistakenly applied. According to ECS, it was not. I am still not so sure, after looking a the ppm vs. temperature test plot they gave me for the -DP part. This chart shows ppm climbing to less than 60ppm at 125C. IMO it should have been included in the spec sheet, and there should have only been one part letter assigned for any combination of ppm and range of T.
Did you mean “-BS”? ‘C’ is not indicated as a valid character for that particular position. Also, there are a handful of -BS coded parts listed for the series, although not for the frequency of apparent interest.
The maxima/minima in the characteristics table are considered a product specification, describing the conditions of test and threshold of performance which can be used to judge claims of defect. In contrast, a test report simply shares behaviors observed across some sample population, and does not imply warranty or guarantee of any sort.
It’s not surprising at all that -DP designated parts guaranteed to 30PPM @ 105C might drift to 60PPM when tested to 125C. It’s unreasonable to take that as some sort of indication that the tested parts should/could have been designated -BS however, because such a result would indicate failure to meet the specification described by that designation.
Rick,
Look again at the spec sheet for the ECS-2520Q-33-480-DP-TR. The conditions of operation clearly indicate -BS and -DP as the only tested conditions.
It is not necessary for a given part number formulation to be specifically enumerated in a characteristics table for an item referenced thereby to offered as an item of trade.
Per the part numbering guide, the -BP designation for this series indicates that parts sold as such are to maintain ±50PPM stability over a -40~105°C temperature range. If process and yield improvements allow, offerings with the more stringent -BS designation may become more numerous.
