Tài liệu BIASING ppt

BIASINGBIASING Diodes,Transistors,Fets Practical Perspective. Prof K Appa raoProf K.Appa rao BIASING DIODES TRANSISTORS FETSDIODES,TRANSISTORS,FETS HOW practical perspective  Semiconductor Diodes.  Sfdid  Specs of diodes,  Determine ckt, apparatus for forward bias.  Reverse bias ckt and apparatus  FUN WITH DIODES BIASING  ZENER DIODES, design supply,estimate rippleripple  TUNNEL DIODES  FUN WITH ZENERS  TRANSISTORS Biasing methods  FUN WITH TRANSISTORS  FETS How to bias difficulties  FETS How to bias, difficulties. DIODESDIODES  FORWARD BIAS  Specs: Vf @ If  REVERSE BIAS  Specs Ir @ Vr Vb Vb IfVb If  Apparatus: DC Power supply  Ammeter , Voltmeter, Diode,  Resistor ,Bread board, Wires  Apparatus: DC Power supply  Ammeter , Voltmeter, Diode,  Resistor ,Bread board, Wires An Engineer specifies thus  Dual/Single Dc Regulated Power supply 0-30v / 1 A ……… 1 No.  Moving coil DC milli ammeter 10 ma FSD… 1 No. 3½di i i i l li C1  3 ½ digit Digital Multi-meter LCD type 1No.  Diode type 1N 4148……. 1 No. Cb Fil it 27k½ 5% 1N  Carbon Film resistor 2.7 k ½ w 5 % …1 No  Bread board….1 No  Single strand 1/20 insulated PVC wires  Single strand 1/20 insulated PVC wires… How to determine R ? I f = 10 ma Vb volts R ohms Pd dissi pation W & tolerance p tolerance 10 820 100 mw ¼ & 5 % 20 1800 200 mw ¼ & 5 % 30 2700 300 mw ½ & 5 % Reverse Bias Characteristic….  A widely used circuit, Is it OK ? what does uA V what does uA read ? V read by analog V V read by analog meter, by DMM ua by DMM THINK. !!! Correct Methods….  Solution 1. 1uF T CRO Ir 1 uF To CRO 1 M ohm 0-30v  I r= Vosc/1 M, say 15 mv/1M =15 nA !! Correct methods  Solution 2  Solution 2 DMM 1 M ohm DMM 0-30v  I r= Vdmm/1 M, say 15 mv/1M =15 nA !! FUNWITHDIODESFUN WITH DIODES Enjoy QUIZ [...]... Clip Waves around zero 1k Vo =? 20v p p p-p sine wave 5v PROBLEM No 6 R1 Vo= V ? 5v 20v p-p sine input 5v BIASING Transistors NPN t transisor i C Ib PNP T Transistor i t Ic Ie B T1 E Ib C B Ic T2 Ie Realtions : Ie = Ib + Ic, Ic = βIb, β= ai/1-ai E BE jn forward biase Rulesd, BC jn reverse biased Biasing (Beta dependant) Fixed Bias with Emitter stabilised feed back Vc Vc Rb Rc T1 Ic = βIb FIXED BIAS . BIASINGBIASING Diodes,Transistors,Fets Practical Perspective. Prof K Appa raoProf K.Appa rao BIASING DIODES TRANSISTORS FETSDIODES,TRANSISTORS,FETS. apparatus  FUN WITH DIODES BIASING  ZENER DIODES, design supply,estimate rippleripple  TUNNEL DIODES  FUN WITH ZENERS  TRANSISTORS . .Biasing methods  FUN