| U |
AEG, Amperex, GI, Philips, NS, Siemens, Signetics, Siliconix, ST, Telefunken, Toshiba, ZMD |
| UA |
Allegro, Fairchild, JRC, Motorola, Philips, SGS, Signetics, TI |
| uA |
Fairchild, Motorola, NS |
| UAA |
Motorola, Philips, TI |
| UAC |
Micronas |
| UART |
NS |
| UC |
IR, Lattice, Motorola, Philips, Samsung, SGS, SiliconGeneral, TI, UMC, Unicorn, Unitrode |
| UCM |
Allegro |
| UCN |
Allegro, SGS, Sprague |
| UCQ |
Allegro |
| UCS |
Allegro, Sprague |
| UDN |
Allegro, Sprague |
| UDP |
Intermetall |
| UDPI |
Intermetall |
| UDS |
Sprague |
| UF |
GI |
| UGN |
Allegro |
| UGS |
Allegro |
| UH |
Sharp |
| UHP |
Sprague |
| uL |
Fairchild, NS |
| ULG |
Allegro |
| ULN |
Allegro, Motorola, NS, SGS, Sprague, TI |
| ULQ |
Allegro |
| ULS |
Sprague |
| UM |
UMC |
| UMA |
Philips |
| UMC |
UMC |
| UMF |
Philips |
| UMH |
Rohm |
| UN |
Matsushita, SGS |
| Unx |
Fairchild, NS |
| UP |
NEC |
| UPA |
Allegro, NEC |
| UPB |
NEC |
| UPC |
Hitachi, NEC |
| UPD |
NCR, NEC, Samsung, Sony |
| UPM |
Datel |
| URF |
Motorola |
| URFR |
Samsung |
| URSF |
Toshiba |
| UST |
SGS |
| UT |
Aeroflex UTMC, UTRON |
| UTD |
NEC |
