• In most cases, we require some form of buffer or driver IC
between the port and the MS LED.
• For example, we can use UDN2585A.
Each of the (8) channels in this buffer can simultaneously
source up to 120 mA of current (at up to 25V): this is
enough, for example, for even very large LED displays.
Note that this is an inverting (current source) buffer. Logic 0
on the input line will light the corresponding LED segment.
