Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M74HC139B1N found under Microcircuit Digita by Stmicroelectronics Ltd. The National Stock Number assigned to this part is 5962013721224, and the Federal Supply Class is 5962 Microcircuits Electronic. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like M74HC139B1N.