Re: Interesting Vintage TTL Logic IC Problem
This is the circuit I used. It went into a PIC microcontroller, but as I was only reading 1 bit it had no problems with 'sloping' edges.
The 7490 types internally have the one 'clk' input connected to 3 or 4 flip-flops, so I don't know how they would switch with 'sloping' inputs, but I would aim for the 5 nS rise and fall times that are used in the datasheet diagrams.
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