CBAmpSu10

# CBAmpSu10 - c Copyright 2010 W Marshall Leach Jr Professor...

This preview shows pages 1–2. Sign up to view the full content.

° Copyright 2010. W. Marshall Leach, Jr., Professor, Georgia Institute of Technology, School of Electrical and Computer Engineering. The Common-Base Ampli f er Basic Circuit Fig. 1 shows the circuit diagram of a single stage common-base ampli f er. The object is to solve for the small-signal voltage gain, input resistance, and output resistance. Figure 1: Common-base ampli f er. DC Solution (a) Replace the capacitors with open circuits. Look out of the 3 BJT terminals and make Thévenin equivalent circuits as shown in Fig. 2. V BB = V + R 2 + V R 1 R 1 + R 2 R BB = R 1 k R 2 V EE = V R EE = R E V CC = V + R CC = R C (b) Make an “educated guess” for V BE . Write the loop equation between the V BB and the V EE nodes. To solve for I C ,th isequat ionis V BB V EE = I B R BB + V BE + I E R EE = I C β R BB + V BE + I C α R EE (c) Solve the loop equation for the currents. I C = αI E = βI B = V BB V EE V BE R BB + R EE (d) Verify that V CB > 0

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 4

CBAmpSu10 - c Copyright 2010 W Marshall Leach Jr Professor...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online