1. Common-Base Amplifier

3. Response of CB Stage to small Input Change

4. Input Impedance

5. Application of CB Stages

6. Response to a Source of Finite Source Resistance

7. Output Impedance

8. Input Impedance

9. General CB (VA=infinity, RB>0) Base resistance (RB) decreases voltage gain.

11. CB Stage with Biasing

12. Design Goal Goal: i2>>i1

13. Bypass Capacitor (Base resistance decreases gain!)

14. Design Guideline Given: Rin, AV Select RE>>(1/gm). – gm →IC. – RE=10Rin Av=g m R C →RC Vb=IERE+VBE Let I(R1)=40IB →(R1+R2) R2 is known from Vb and R1. 1/(C1ω)=(1/gm)/20 1/(beta+1)/(C1 ω)=(1/gm)/20

15. Common Base Amplifier

16. ADS Simulation ADSAnalysis Vs,pp(mV)44 Vin,pp(mV)21.90 Vout,pp(mV)17N/A Vout,pp/Vin,pp8.511 Vout,pp/Vs,pp4.255.23