possible flip-flop needed?

Thread Starter


Joined Feb 23, 2009
I have two inputs (in1, in2) and need an output (out). I need the leading edge of in1 to cause a high output and the FIRST leading edge of in2 to cause output to toggle low if it was high. And the trailing edge of in2 to toggle output low if it was high (reset I guess).

If in1 is low, then in2 will always be low.

I have a 4027 flip-flop j-k cmos. (M4027BP to be percise). The inputs are coming from two comparators. Comparator ref for in1 is set lower than comparator ref for in2. And the same input is used for both comparators.

How would a circuit around the 4027 look to get the desired output?



Joined Mar 24, 2008
To me it looks like when in2 is high the ouput is low, always. Most flip flops trigger on the negitive edge, you may need to invert the signal on in1 to properly toggle the 1st flip flop.

The 2nd flip flop goes low when in2 goes high, a reset function. Merge the two.