Embedded analogue nonvolatile memory with feedback-controlled programming circuit on-chip

An analogue nonvolatile memory is presented, which is not only CMOS-compatible but also capable of storing analogue currents with a resolution of more than eight bits. The programming process is controlled by a hysteretic comparator on-chip, which stops the injection current automatically by negative feedback, regardless of the programming nonlinearity and device mismatches. With the simple, on-chip programming circuit, the proposed analogue memory is capable of storing currents ranging from 1 to 18 μA accurately with negligible variations across different memory cells.