This application note includes all comparators devices listed in Table 1-1 including the next generation B-versions which have improved specifications. All of these comparators contain a unique input stage that was revolutionary when released in the early 1970's. Unlike other comparators of that time, the family supported ground level input voltages useful for single supply designs.

The base part numbering is unconventional, as the numbering was assigned in order of product development. The LMx39/LM2901 quad was released first, followed by the LMx93/LM2903 dual, then followed by the TL331 (TI) and LM397 (National) singles several years later. The -Q1 suffix denotes AEC-Q100 qualified devices. The “-N” in a part name denotes devices acquired from the National Semiconductor acquisition that matched an existing Texas Instruments (TI) base part number. There are no current orderable part number duplicates because National Semiconductor and TI used different package suffixes. Likewise, the next generation versions have the suffix B added which indicates improved specifications. We refer to all the devices listed in Table 1-1 as the LM339 Family throughout this document.