A' and 'B' suffix on HMC parts

Question We are using HMC194MS8 on a LTB of 25:04:15. The suggested replacement is HMC194AMS8E. The suffix E denotes Lead Free but what is the additional "A"? Answer The suggested replacement is HMC194AMS8E is a form, fit and functional alternative to HMC194MS8/HMC194MS8E. We are exiting from a foundry. This part is from a different foundry and process, different design but targeted with same/better electrical performances and specifications. In general, the HMC products that have 'A' suffix on the part number (p/n) are translated versions of related HMC products without 'A' suffix on the p/n. This can be due to a foundry change and/or more specifically due to a die change. Similarly, the HMC products that have 'B' suffix on the p/n are the translated versions of related HMC products with 'A' suffix on the p/n. The replacement products are in the same package/pin outs and support the same (or better) operating conditions and electrical specifications as the discontinued products. However, related to a specific HMC part with 'A' and 'B' kindly contact us to know about the form, fit, function and drop-in replacement assurance of the alternative and a comparison between the datasheet has to be made for more information. PCN: http://hittite.com/Lyris/PCN/PCN130009.pdf For this specific p/n it is a FFF alternative. We can look for more information on such requests over PCNs/PDNs. Currently, the Hittite related information regarding discontinued products (datasheets/replacement alternatives/announce/LTB) can be found on: http://www.hittite.com/products/index.html/archive Another useful link on EZ for this discussion is: https://ez.analog.com/message/168399#168399