J601_lec03

5th Year, Integrated Technical Education Cluster AlAmeeria‎
lec#3, Electronic Principals

Transcript

1. Lecture #3 BJT Transistors & DC Biasing Instructor: Dr. Ahmad El-Banna November 2014 J-601-1448 Electronic Principals Integrated Technical Education Cluster At AlAmeeria‎ © Ahmad El-Banna
2. Agenda 2 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna Transistor Construction & Operation Transistor Configurations Transistor Testing & Terminal Identification Transistor DC Bias Configurations Design Operations Various BJT Circuits &Troubleshooting Techniques Practical Applications
3. Transistor Construction • Basic BJT Constructions 3 • Basic BJT symbols and Currents J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
4. Transistor Operation • Basic Operation using pnp transistor. 4 • Majority and minority carrier flow of a pnp transistor. • Biasing a transistor: (a) forward-bias (b) reverse-bias. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
5. BJT CONFIGURATIONS • Common Base • Common Emitter • Common Collector 5 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
6. Configurations: Common Base • Notation and symbols used with the common-base configuration: (a) pnp transistor; (b) npn transistor. 6 • Input or driving point characteristics for a common-base silicon transistor amplifier. • Output or collector characteristics for a common-base transistor amplifier. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
7. Configurations: Common Base.. • Formulas: 7 • Biasing of a CB pnp tr. in the active region: J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
8. Configurations: Common Emitter 8 • Notation and symbols used with the common-emitter configuration: (a) pnp transistor (b) npn transistor. • Characteristics of a silicon transistor in the common- emitter configuration: (a) collector characteristics (b) base characteristics. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
9. Configurations: Common Emitter.. 9 • Formulas: • Biasing of a CE npn tr. in the active region: J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
10. Configurations: Common Collector 10 • Notation and symbols used with the common-collector configuration: (a) pnp transistor; (b) npn transistor. • Common-collector configuration used for impedance-matching purposes. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
11. Configurations: Common Collector.. 11 • Defining the linear (undistorted) region of operation for a transistor. • Formulas: J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
12. PRACTICAL VIEW • Transistor Spec. Sheets • Transistor Testing • Transistor Casing and terminals identification • Transistor Development 12 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
13. Transistor Specification Sheets 13 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
14. Transistor Specification Sheets.. 14 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
15. Transistor Testing using Curve Tracer 15 • Check the beta value: Curve tracer response to 2N3904 npn transistor. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
16. Transistor Testing using Transistor Tester 16 • Transistor testers: (a) digital meter (b) dedicated testers. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
17. Transistor Testing using Ohmmeter 17 • Checking the forward- biased base-to-emitter junction of an npn transistor. • Checking the reverse- biased base-to-collector junction of an npn transistor. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
18. Transistor Casing 18 • Various types of general-purpose or switching transistors: (a) low power (b) medium power (c) medium to high power. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
19. Terminal Identification 19 • Transistor terminal identification. • Internal construction of a Fairchild transistor in a TO-92 package. • Type Q2T2905 Texas Instruments quad pnp silicon transistor: (a) Appearance (b) pin connections. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
20. TRANSISTOR DC BIAS CONFIGURATIONS • Fixed-Bias Configuration • Voltage-Divider Bias Configuration • Emitter-Follower Configuration 20 • Biasing means applying of dc voltages to establish a fixed level of current and voltage. >>> Q-Point J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
21. Fixed-Bias Configuration 21 • Fixed-bias circuit. • DC equivalent ct. • Base–emitter loop. • Collector–emitter loop. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
22. Fixed-Bias Configuration Example 22 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
23. Fixed-Bias Configuration ... 23 • Load Line Analysis J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna Saturation Current
24. Voltage-Divider Configuration 24 • Exact Analysis • Voltage-divider bias configuration. • DC components of the voltage-divider configuration. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
25. Voltage-Divider Configuration 25 • Approximate Analysis • Transistor Saturation • Load-Line Analysis J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
26. Voltage-Divider Configuration Example 26 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
27. Emitter-Follower Configuration 27 i/p ct o/p ct • dc equivalent ct • Common-collecter (emitter-follower) configuration. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
28. Summary Table 28 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
29. Summary Table.. 29 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
30. DESIGN OPERATION 30 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
31. Design Operations 31 • The design process is one where a current and/or voltage may be specified and the elements required to establish the designated levels must be determined. • The design sequence is obviously sensitive to the components that are already specified and the elements to be determined. If the transistor and supplies are specified, the design process will simply determine the required resistors for a particular design. • Once the theoretical values of the resistors are determined, the nearest standard commercial values are normally chosen and any variations due to not using the exact resistance values are accepted as part of the design. J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
32. Design Operations Example 32 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
33. VARIOUS BJT CIRCUITS • MULTIPLE BJT NETWORKS • CURRENT MIRRORS • CURRENT SOURCE CIRCUITS • Bipolar Transistor Constant-Current Source • Transistor/Zener Constant-Current Source • PNP TRANSISTORS • TRANSISTOR SWITCHING NETWORKS 33 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
34. MULTIPLE BJT NETWORKS 34 • R–C coupling • Darlington configuration J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
35. CURRENT MIRRORS 35 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
36. CURRENT SOURCE CIRCUITS 36 • Bipolar Transistor Constant-Current Source • Transistor/Zener Constant-Current Source J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
37. pnp TRANSISTORS 37 TRANSISTOR SWITCHING NETWORKS J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
38. TRANSISTOR SWITCHING NETWORKS.. 38 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
39. TROUBLESHOOTING TECHNIQUES 39 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
40. TROUBLESHOOTING TECHNIQUES • For an “on” transistor, the voltage VBE should be in the neighborhood of 0.7 V. • For the typical transistor amplifier in the active region, VCE is usually about 25% to 75% of VCC . 40 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
41. PRACTICAL APPLICATION • BJT Diode Usage and Protective Capabilities • Relay Driver • Alarm System with a CCS • Voltage Level Indicator • Logic Gates 41 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
42. Practical Application 42 • BJT Diode Usage and Protective Capabilities • Relay Driver J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
43. Practical Application… 43 • Alarm System with a CCS • Voltage Level Indicator J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
44. Practical Application…. 44 • Logic Gates J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna
45. • For more details, refer to: • Chapter 3 & 4, Electronic Devices and Circuits, Boylestad. • The lecture is available online at: • https://speakerdeck.com/ahmad_elbanna • For inquires, send to: • ahmad.elbanna@fes.bu.edu.eg 45 J-601-1448 , Lec#3 , Nov 2014 © Ahmad El-Banna