CMOS current-mode outstar neural networks with long-period analog ratio memory

An on-chip learnable neural network called the outstar is implemented in CMOS current-mode circuits. The on-chip memory called the ratio memory can retain the stored ratio values. The outstar chip is fabricated and tested. It has shown that the storage time of the ratio memory can be as long as 5 minutes without refreshment. Moreover, the outstar can normalize the input pattern and enhance the contrast of the stored pattern within a long period. The application of the outstar in pattern classification has been demonstrated