--- In TekScopes@..., KeepIt SimpleStupid <keepitsimplestupid@...> wrote:
Not necessarily.?? If you have a block diagram and a description of the device that you want to replace, post it.?? From there, maybe we as a group could suggest what might be able to be used to substitute the internals.
In addition to its logic diagram, you need to look at the circuit it is used in.
Because Tek made ICs are single sourced, Tek engineers could rely on parameters that are typically "unspecified" as being consistent.
Things such as input and input impedances, pull up resistor values, Ft and Miller C of the transistors, etc. would not change as they may with different vendors' version of the same logic circuit. Hence, in Tek designs you often see analog signals driving inputs or outputs driving analog signals which depend on these characteristics. Simple substitution of a functionally logic equivalent circuit may not operate if these conditions are not duplicated, possibly using external components.
The first Tek made ICs of the part numbers you mentioned were fabricated on a 200 ohm/square process ¨C Tek's first. This is not a very fast process (transistor Ft and switching speed) by today's standards. In some cases you may need to slow down output transitions to substitute FPGA equivalents.
- Steve
