ADD-ON CARD WITH AUTOMATIC BUS POWER LINE SELECTION CIRCUIT

摘要

An add-on card (200) is provided for use within a computer system (100) that has an expansion slot connected to a bus (106). The bus (106) has a first supply line (214) for supplying a first predetermined voltage and a second supply line (212) for supplying a second predetermined voltage which is higher than the first predetermined voltage. The add-on card (200) is adapted to operate properly regardless of whether the respective predetermined voltages are supplied on (1) the first supply line (214) only, (2) the second supply line (212) only, or (3) both supply lines (212, 214). In a PCI bus implementation, where 3.3V and 5V are the predetermined voltage levels, the add-on card (200) operates properly regardless of whether: only a 5V level is provided, only a 3.3V level is provided, or both 3.3V and 5V levels are provided.