When buying common integrated circuits like 555, 741 and others I noticed that many of them have suffixes. What do these suffixes mean?
For Integrated Circuits suffixes can have different meanings. They may, for example, mean the type of wrapping. For an LM350T, for example, the T indicates plastic casing while the LM350K has a metal casing. In other cases, the suffix may indicate a special edition of the component in which the arrangement of the terminals is different from the traditional one. Another pin instead of 7 to ground in a 14-pin CMOS, for example. Finally we have cases where the characteristics of the component itself are differentiated or even the internal circuit. For example, a given suffix may indicate that the component does not have an internal pull-up resistor and that it must be externally connected. The best in case of doubt is to consult the data sheet taking into account the suffix when looking for it.
