Design Of A One Time Programmable Memory Based On Standard CDMOS Process

Memory is simply to save the information of component,which is used for data exchange and information stored in major media,its role has not be ignored.There is a important demand for it in the further,not only erase the memory of fast speed and energy consumption,but also to ensure the safety norms layouts.Embedded programmable memory can be written to only once a program,it is characterized not only flexible and easy to use,but also the price is low,it has become the preferred of circuit design and application in modern election.Nonvolatile memory because of high integration, low cost, fast work rate and own technology to optimize its growth prospects has become increasingly important.OTP(One Time Programmable) is a one-time programmable memory,although it is only to be write once when the factory burned,but it widely used especially used to make the circuit Trimming.The one time programmable memory even when power is turned off but can save the information, so it can be used to provide a variety of flexible and affordable solutions for circuit applications.Although the circuit will used fuse to Trim circuit,in order to precisely trimming current or voltage accurately.But in the process with a fuse trimming circuit often encounter constantly burning fuse or burn the chip problem,there is the problem of voltage deviation caused by the melting line after trimming package, so in this trim circuit use the OTP to do is necessary.So the company which I practiced that design of such a chip, this chip is use of HJTC 0.35 um CDMOS 3.3V / 5.0V / 40 V 2P5M P-sub Polycide fabrication.The capacity of the chip is 32 bits. The chip is controlled by an external clock data interface to perform write operations.In the chip internal can use chip clock and reset signals to read data automatically, after reading the data closed circuit to save power.First of all,describing the theoretical basis of the OTP memory,and then discussed the working principle of the storage unit,including programming,reading and writing and erasing process.Finally,in circuit design analysis the design methods.In the design of the memory peripheral circuit, there are critical timing control circuits, latches and address decoding circuitry in the core shows the internal OTP module, mainly in the high and low voltage conversion circuit, the DC bias circuit and sense amplifier module, and then simulation and analysis.Then the project is completed according to the design of the circuit layout of the overall layout design and verification inspection.Finally, the layout module for presentations and sensitive process of drawing the whole layout and analyzed data for subsequent layout, parasitic parameters need to be operated by an integrated circuit design software, so there is no detailed description.When the final chip tape out chip test to see if it works correctly and in conformity with the design parameters.