SEMICONDUCTOR DEVICE PHYSICS AND DESIGN

7.3. TEMPORAL RESPONSE OF A SCHOTTKY DIODE 317 The general solution of the equation is Qp(t)=iRτp+Ce−t/τp (7.2.52) To obtain the ...

318 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS Cgeom C Ls d Rd Rs Figure 7.6: Equivalent circuit of a Schott ...

7.4. BIPOLAR JUNCTION TRANSISTORS: A CHARGE-CONTROL ANALYSIS 319 relationship between the currents and the stored charge, the ch ...

320 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS It is useful to examine the charge in the device in the forwa ...

7.4. BIPOLAR JUNCTION TRANSISTORS: A CHARGE-CONTROL ANALYSIS 321 VCC RCC C vout B vin E (a) (b) n+ - E p - B n- - C - ΔQBE +ΔQBE ...

322 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS This is valid at current densities much below the Kirk thresh ...

7.4. BIPOLAR JUNCTION TRANSISTORS: A CHARGE-CONTROL ANALYSIS 323 Forward- biased EBJ Total minority charge Forward- biased BCJ Q ...

324 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS so that we have iB(t)− IC(EOS) βF = QS τS + dQS dt (7.4.22) W ...

7.5. HIGH-FREQUENCY BEHAVIOR OF A BJT 325 B VBE(sat) E C VCE(sat) B C E + – + – Figure 7.9: The BJT and a simple model for a dev ...

326 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS applied at the base terminal, resulting in an output voltagev ...

7.5. HIGH-FREQUENCY BEHAVIOR OF A BJT 327 (a) 0 wB Δnp(0) |ΔQF| (b) 0 wB Δnp(0) |ΔQF| Δnp(wB) Figure 7.10: Charge profile in the ...

328 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS RC B E C RE AC short Figure 7.11: Biasing circuit for calcula ...

7.5. HIGH-FREQUENCY BEHAVIOR OF A BJT 329 Inserting the above equation and equation 7.5.12 into equation 7.5.10 gives us forτBC ...

330 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS (a) ve(x) wd,BC x (b) |eΔn(x)| wd,BC x ΔQC ΔQ'C Figure 7.12: ...

7.5. HIGH-FREQUENCY BEHAVIOR OF A BJT 331 (b) E(x) wC x (a) |eΔn(x)| wC x d(ΔQC) d(ΔQ'C) dx dE+(x) dE-(x) Figure 7.13: Induced ( ...

332 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS Example 7.1Consider annpntransistor with the following proper ...

7.5. HIGH-FREQUENCY BEHAVIOR OF A BJT 333 n+ - E p - B n- - C n+ wB wd,BC iB iE iC iω( 0 ) iω(wB) VCE VBE (t) Figure 7.14: Curre ...

334 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS We assume solutions of the form n(x, t)=ndc(x)+nω(x)ejωt (7.5 ...

7.5. HIGH-FREQUENCY BEHAVIOR OF A BJT 335 We see that the injected current amplitude is complex, indicating that the current has ...

336 CHAPTER 7. TEMPORAL RESPONSE OF DIODES AND BIPOLAR TRANSISTORS ΔJc ΔJc=eΔn(x)Δx/τ τ= Wc/vs ΔQc ΔQc vs Δn(x) Wc Δ x x BASE Fi ...