Based On Floating Gate Mos Devices, Digital Circuit Design

With the development of the IC (Integrated Circuit) technology, many problems have occurred for the traditional silicon IC based on single transistor function. As a new and functional transistor, floating-gate MOS provides us an effective way to solve the problems resulted from the increase of the number of transistors and the interconnections. In this paper, based on analysis of the device's work theory, characteristics and the SPICE model for this device, using the switch-signal theory, some new designs of the digital circuits at switch level,such as basic gate circuits , the encoder-decoder circuits , Schmitt trigger , D latch and Dflip-flop, are proposed.Basic gate circuits and the encoder-decoder circuits based on floating-gate MOS are designed. The detailed design methods are given. They are simulated by HSPICE. The results show these circuits have correct logic function. Compared with the previous design, these circuits have the advantages of simple configuration, low propagation delay. They can be implemented by a standard double-poly silicon CMOS process.Based on the threshold-controllable technique, a new simple Schmitt trigger using floating-gate MOS is proposed. And more, we propose a new design whose voltage hysteresis can be adjusted by external controlling voltage. Compared with the previous design, the adjusting method of this design is more convenient and practicable.D latch and D flip-flop circuits using floating-gate MOS are designed. In order to introduce the application of D flip-flop, we design the register and counter by D flip-flops. They are simulated by HSPICE. The results show that these circuits have correct logic function. They have good future in the design of the sequential circuits.