From the engineering requirements, 2 state models for the schottky barrier diode and 4 state models for the schottky clamped transistor have been set up. Two typical circuits are analyzed and researched. 从工程实际出发,分别建立了肖特基势垒二极管(SBD)二态模型和肖特基钳位三极管(SCT)四态模型的电路模型,分析并研究了这两个典型的应用电路。