Simple level conversion circuit diagram

　　The level shifting circuit consists of fast switching transistors Q1 and Q2. The user selects level shifting high and shifting low, which are the DC bias voltages connected to the emitters of the transistors to match the desired output high logic level. and low logic level . C1, R1, D1, C2, R2 and D2 keep the base voltage of Q1 and Q2 close to the emitter voltage.