1. Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 21.1 Example – see Example 21.2 from course text Determine the quiescent output voltage of this circuit

2. Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 21.2 Base current is small, so Emitter voltage V E = V B – V BE = 2.7 – 0.7 = 2.0 V Emitter current Since I B is small, collector current I C  I E = 2 mA Output voltage = V CC – I C R C = 10 - 2 mA  2.2 k  = 5.6 V

3. Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 21.3  A common-collector amplifier –unity gain –high input resistance –low output resistance –a very good buffer amplifier

4. Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 21.4 Other Bipolar Transistor Applications  A phase splitter 21.7

5. Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 21.5  A voltage regulator

6. Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 21.6  A logical switch