Signal coincidence detection circuits and methods implemented in such
circuits are disclosed. An example signal coincidence detection circuit
includes a first differential transistor pair, a second differential
transistor pair coupled with the first differential transistor pair and a
third differential transistor pair coupled with the first differential
transistor pair in parallel with the second differential transistor pair.
The circuit also includes a first input signal terminal coupled with the
first, second and third differential transistor pairs, wherein, in
operation, the first input signal terminal receives a first input signal
that is communicated to the first, second and third differential
transistor pairs. The circuit further includes a second input signal
terminal coupled with the first, second and third differential transistor
pairs, wherein, in operation, the second input signal terminal receives a
second input signal that is communicated to the first, second and third
differential transistor pairs. The circuit additionally includes a
current source coupled with the first differential transistor pair,
where, in operation, a plurality of currents of the second and third
differential transistor pairs are combined such that the combined
currents indicate whether or not coincidence between the first and second
input signals exists.