Neuromorphic device and a synapse network including a post-synaptic neuron having a subtracting circuit

A synapse network of a neuromorphic device, the synapse network comprising:

• a first synapse layer;
• and
• a second synapse layer,
• wherein the first synapse layer comprises:
• a plurality of first pre-synaptic neurons;
• a plurality of first row lines extending from the plurality of first pre-synaptic neurons, respectively;
• a plurality of first post-synaptic neurons;
• a plurality of first column lines extending from the plurality of first post-synaptic neurons, respectively;
• and
• a plurality of first synapses coupled between the plurality of first row lines and the plurality of first column lines, respectively, the plurality of first synapses being disposed in a plurality of intersection regions between the plurality of first row lines and the plurality of first column lines, respectively, and
• wherein the second synapse layer comprises:
• a plurality of second pre-synaptic neurons;
• a plurality of second row lines extending from the plurality of second pre-synaptic neurons, respectively;
• a plurality of second post-synaptic neurons;
• a plurality of second column lines extending from the plurality of second post-synaptic neurons, respectively;
• and
• a plurality of second synapses coupled between the plurality of second row lines and the plurality of second column lines, respectively,
• wherein:
• each of the plurality of first post-synaptic neurons comprises a first subtracting circuit,
• each of the plurality of second post-synaptic neurons comprises a second subtracting circuit,
• the plurality of first post-synaptic neurons and the plurality of second pre-synaptic neurons are electrically connected with each other, respectively,
• the first pre-synaptic neuron provides first electrical pulses to the first synapse through the first row line,
• the first post-synaptic neuron receives a first column current from the first synapse through the first column line,
• the second pre-synaptic neuron provides second electrical pulses obtained from the first column current to the second synapse through the second row line,
• the second post-synaptic neuron receives a second column current from the second synapse through the second column line,
• a number of the plurality of first row lines is greater than a number of the plurality of first column lines,
• a number of the plurality of first column lines is equal to a number of the plurality of second row lines, and
• a number of the plurality of second row lines is greater than a number of the plurality of second column lines.

A neuromorphic device comprising:

• a plurality of pre-synaptic neurons;
• a plurality of row lines extending from the pre-synaptic neurons in a row direction;
• a plurality of post-synaptic neurons;
• a plurality of column lines extending from the post-synaptic neurons in a column direction;
• and
• a plurality of synapses coupled between the row lines and the column lines,
• wherein each of the post-synaptic neurons comprises a subtracting circuit,
• wherein the subtracting circuit includes a non-inverting input terminal connected to one of the column lines, an inverting input terminal connected to a reference current source, and an output terminal to output a current difference between a column current received from each of the synapses and a reference current provided from the reference current source.