Slide 1OutlineLearning objectivesContext for this moduleDiode Types and Circuit SymbolsP-N Junction – Forward BiasP-N Junction – Reverse BiasI-V Characteristic for a Diode (non-linear)I-V Characteristic for a Zener DiodeDiode Example 1Diode Example 2Diode ApplicationsBipolar Junction Transistor (BJT)BJT Operation (conceptual)BJT low-side driveBJT low-side drive exampleBJT high-side driveThe Darlington pairThe MOSFETThe MOSFET (hydraulic analogy)MOSFET high and low-side drive examplesBJT vs. MOSFET – which to use?Switching loads with having appreciable inductanceChoosing the transient suppression componentsPWM on the mbedPwmOut Classmbed overviewmbed pinoutsSlide 29Starboard OrangeFor More InformationBJ Furman20SEP2011Interfacing to Control Powerhttps://www.jameco.com/Jameco/Products/ProdImag/1939589.jpgIntroduction to Mechatronics, Figure 17.16, p. 410.http://arduino.cc/en/uploads/Main/ArduinoDuemilanove.jpgOutline01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1062Learning objectivesContext for this moduleDiodesBipolar junction transistors (BJT)MOSFETsUsing transistors to control powerLearning objectives01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1063Explain the theory, construction, and behavior of a diodeExplain the theory, construction, and behavior of a bipolar junction transistor (BJT)Explain the theory, construction, and behavior of a MOSFETDesign an interface between a microcontroller and device that needs significant powerContext for this moduleSystem toControlSensorSignalConditioningController(Hardware & Software)PowerInterfaceActuatorUserInterfacePowerSourceBJ Furman 22JAN2011ME 106ME 154ME 157ME 195ME 120ME 284ME 106ME 120ME 30ME 106ME 190ME 187ME 110ME 136ME 154ME 157ME 182ME 189ME 195ME 106ME 120ME 106INTEGRATIONMechatronics Concept Map‘Muscle’01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1064Diode Types and Circuit SymbolsDiode TypesSignal DiodesRectifier DiodesLight Emitting Diodes Zener DiodesAnode(P)Cathode(N)Symbol:Actual Device:Anode(P)Cathode(N)01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1065P-N Junction – Forward BiasP TypeDoped with Boron or Gallium(1 Less e-)N TypeDoped with Arsenic or Phosphorous(1 Extra e-) Anode(P)Cathode(N)+ -Holese-Net currentA Diodeis formed byA junction between positively and negatively doped semiconductor materialP N01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1066P-N Junction – Reverse BiasP TypeDoped with Boron or Gallium(1 Less e-)N TypeDoped with Arsenic or Phosphorous(1 Extra e-) Anode(P)Cathode(N)- +P NHolese-No net current01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1067I-V Characteristic for a Diode (non-linear)VIForward BiasAnode voltage higher than cathode voltageReverse Bias Cathode voltage higher than anode voltageIV Characteristic for a ResistorBreakdown Voltage50-1000V0.6 to 0.7 V for silicon diode,For LED ~ 1.5 V (IR) – 3.8 V (Blue)= 1/RWhy do you need a resistor in series with a diode?Anode(P)Cathode(N)01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1068I-V Characteristic for a Zener DiodeAnode(P)Cathode(N)Introduction to Mechatronics, Figure 10.8, p. 203.01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 1069Find VD, IR, VRDiode Example 1+ VD -+ VR -IR- 10V+VD = -10V, VR = 0, IR = 001/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10610Find VD, IR, VR , R = 1Ω Diode Example 2+ VD -+ VR -IR+ 10V-VD = 0.7VVR = 10 – 0.7 = 9.3VIR = 9.3 / 1 =9.3A01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10611Diode Applications01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10612AC Rectification Half wave+ VD -+ VR -IR- 10V+~Full waveBipolar Junction Transistor (BJT)01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10613Construction and schematicSo,B-C and B-E junctions look like…?Remember this!Introduction to Mechatronics, Figure 10.15, p. 206.BJT Operation (conceptual)01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10614Like a current-controlled valve where base-emitter current controls collector-emitter currentHydraulic analogy for NPNHow much ‘pressure’ (i.e., voltage, VBE) is needed to cause iBE?Introduction to Mechatronics, Figure 10.16 p. 206.Introduction to Mechatronics, Figure 10.17 p. 207.Key conceptsMust turn on B-E diode to get C-E currentIc = hfeIB (up to saturation)Introduction to Mechatronics, Figure 10.18 p. 207.BJT low-side drive01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10615For mechatronics, transistors are mostly used as electronically controlled switchesEither fully off (cut off) or fully on (saturated)Want to avoid the in-between condition (linear region). Why…?Minimize power dissipation in the transistor-4 -3 -2 -1 0 1 2 3 4 5 6051015Vce vs. VinVin, voltsVce , volts-4 -3 -2 -1 0 1 2 3 4 5 60510152025Ic vs. VinVin, voltsIc, m A-4 -3 -2 -1 0 1 2 3 4 5 600.020.040.060.08Pt vs. VinVin, voltsPt, W-4 -3 -2 -1 0 1 2 3 4 5 600.050.10.150.20.250.3Pload vs. VinVin, voltsPload , WConsiderhfe= 100 (current gain)V+= 12 VVce(sat)= 0.3 VRB= 10 kohmsRload=500 ohmsPlot Vce, Ic, Pt, and Pload vs. VinIntroduction to Mechatronics, Figure 10.18 p. 207.BJT low-side drive example01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10616Find RB to turn on the lamp (Rload) R= 100 ohmsVce(sat)= 0.3 VV+= 10 VVin = 3.3 VProcedureWork backward starting with the load What Ic is needed for saturation? Find a transistor that will handle Ic and V+ (data sheet)Determine hfe and Vce(sat) at Ic(sat) from the data sheetDetermine iB(minimum) to saturate the transistor:Select RB to give iB with some extra margin (2x – 10x): LoadLoadLoadCEsatRVRVVRVV vely conservatimost or ,)2.0(velyconservati moreor ,)(2010 thumb,-of-ruleor ,toiihiiCEsatBfeCEsatB 216.0BinBiVVRBJT high-side drive01/14/2019BJ Furman SJSU Mechanical and Aerospace Engineering ME 10617Uses a PNP transistorTurn on by making Vin at least 0.6 V lower than V+Turn off by making Vin at least 0.6 V higher than V+ Introduction to Mechatronics, Figure 10.23 p. 210.Introduction to Mechatronics, Figure 10.24 p. 211.The Darlington pair01/14/2019BJ Furman SJSU