ELL100: INTRODUCTION TO ELECTRICAL ENGG. Course Instructors: J.-B. Seo, S. Srirangarajan, S.-D. Roy, and S. Janardhanan Department of Electrical Engineering, IITD
Ability to conduct electricity Insulator Material Resistivity Conductivity Glass Sulphur Quartzfused Conductor Material Resistivity Conductivity Silver Copper Aluminium
Ability to conduct electricity Insulator Material Resistivity Conductivity Glass Sulphur Quartzfused Conductor Material Resistivity Conductivity Silver Copper Aluminium
Ability to conduct electricity Insulator Material Resistivity Conductivity Glass Sulphur Quartzfused - - - - - - - - - - - Conductor Material Resistivity Conductivity Silver Copper Aluminium - - - - - - - - - - - - - - - - - - - - - - -
Ability to conduct electricity Semiconductor Material Resistivity Conductivity Germanium Silicon - - - - - - - - - - -
Ability to conduct electricity Semiconductor Material Resistivity Conductivity Germanium Silicon - - - - - - - - - - - External energy
Ability to conduct electricity Semiconductor Material Resistivity Conductivity Germanium Silicon - - - - - - - - - - - External energy
Drift current of Intrinsic semiconductor
Drift current of Intrinsic semiconductor
Drift current of Intrinsic semiconductor
Drift current of Intrinsic semiconductor
Drift current of Intrinsic semiconductor
Doped Semiconductor n-type
Doped Semiconductor p-type n-type
Doped Semiconductor Recombination In a semiconductor, the mobile electrons and holes tend to recombine and disappear The rate of recombination For the doped and intrinsic semiconductors,
Doped Semiconductor Recombination In a semiconductor, the mobile electrons and holes tend to recombine and disappear The rate of recombination For the doped and intrinsic semiconductors,
Doped Semiconductor Recombination In a semiconductor, the mobile electrons and holes tend to recombine and disappear The rate of recombination For the doped and intrinsic semiconductors, we have
Doped Semiconductor Conductivity of dopped semiconductor In a typical n-type material, donor atoms provide a mobile electron concentration Using Increasing reduces Conductivity of the doped semiconductor is determined by the doping concentration
Doped Semiconductor Conductivity of dopped semiconductor In a typical n-type material, donor atoms provide a mobile electron concentration Using Increasing reduces Conductivity of the doped semiconductor is determined by the doping concentration
Doped Semiconductor Conductivity of dopped semiconductor In a typical n-type material, donor atoms provide a mobile electron concentration Using Increasing reduces Conductivity of the doped semiconductor is determined by the doping concentration
Doped Semiconductor Diffusion current Non-uniform concentration of electric charges enables the charges to move from a high concentrated region to a low one.
Doped Semiconductor Diffusion current Non-uniform concentration of electric charges enables the charges to move from a high concentrated region to a low one.
Doped Semiconductor Diffusion current Non-uniform concentration of electric charges enables the charges to move from a high concentrated region to a low one. The diffusion current crossing a unit:
Doped Semiconductor Total current in a semiconductor Diffusion current Drift current Diffusion current movement caused by variation in the carrier (hole or carrier) concentration Drift current movement caused by electric fields. Direction of the diffusion depends on the slope of the carrier concentration Direction of the drift current is always in the direction of the electric field. Total current in a semiconductor
Doped Semiconductor Total current in a semiconductor Diffusion current Drift current Diffusion current movement caused by variation in the carrier (hole or carrier) concentration Drift current movement caused by electric fields. Direction of the diffusion depends on the slope of the carrier concentration Direction of the drift current is always in the direction of the electric field. Total current in a semiconductor
Doped Semiconductor Total current in a semiconductor Diffusion current Drift current Diffusion current movement caused by variation in the carrier (hole or carrier) concentration Drift current movement caused by electric fields. Direction of the diffusion depends on the slope of the carrier concentration Direction of the drift current is always in the direction of the electric field. Total current in a semiconductor
Doped Semiconductor Total current in a semiconductor Diffusion current Drift current Diffusion current movement caused by variation in the carrier (hole or carrier) concentration Drift current movement caused by electric fields. Direction of the diffusion depends on the slope of the carrier concentration Direction of the drift current is always in the direction of the electric field. Total current in a semiconductor
Doped Semiconductor n-type p-type
p-n Junction + + + + + + + + + + + + + + + + + + + + + + + + + + + + + — — — — — — — + + + + + + + + + + + — — — — + — + — — — + + — + — — — + + — — + + + + + — — + — + + + — — + + + — — — — — — + + + + — + + — — — — + — + + — — + + + + — — + + — + — — — + + + + + + + + — + — — + + — — + — + — — — — — + — + + + + — + — — — + + + + + — — —
p-n Junction + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Free moveable charges recombine => Depletion region — — — — — — — + + + + + + + + + + + + — — — — — — — + + + — + — — — + — — + + + + + — — + — + + + + + + + — — — — — + + + + — + + + + — + + — + — — — — — + — + + — + + — — + + + + + + + + — + — + — — — — — + + + + — + + + + — — + + + + — — + + — — — — Potential difference = built-in potential
p-n Junction — +
p-n Junction — +
p-n Junction — +
p-n Junction — +
p-n Junction Reverse bias — — — — — — — + + + + + + + — — — — — — + +
p-n Junction — +
p-n Junction Forward bias — — — — + + + + — — — + + + — — — — — — + +
p-n Junction Forward bias — — + + + + — — — — — + + + — — — — — — + + The direction of current flow is opposite to electron-flow Forward bias — — + + + + + + — — — — — — — + + + — — — — — — + + + + + + + — — — — — — + + + + + + + — — — — — — + + + + + + +
Diode
Diode
Circuit with diode – 1
Circuit with diode – 1 Turn-on voltage
Circuit with diode – 1
Circuit with diode – 1
Circuit with diode – 1
Circuit with diode – 1
Circuit with diode – 1
Circuit with diode – 1
Circuit with diode – 2
Circuit with diode – 2
Circuit with diode – 2
Circuit with diode – 2
Circuit with diode – 3 – +
Circuit with diode – 3 – +
Circuit with diode – 3 – + + –
Circuit with diode – 4 + + – –
Circuit with diode – 4 + + – –
Circuit with diode – 4 + + – –
Circuit with diode – 4 + + – –
Circuit with diode – 4 + + – –
Circuit with diode – 3 (p. 96)
Circuit with diode – 3 (p. 96)
Circuit with diode – 3 (p. 96)
Diode: Full-wave rectifier
Diode: Full-wave rectifier
Diode: Full-wave rectifier
Diode: Capacitor filter By initial charges in the capacitor During the positive half cycle, the source voltage increases and the capacitor discharges
Diode: Capacitor filter By initial charges in the capacitor During the positive half cycle, if the source voltage is greater than the capacitor voltage the diode will conduct, and the capacitor charges rapidly (C is small) As the input starts to go negative, the diode turns off and the capacitor will slowly discharge through the load
Diode: Capacitor filter By initial charges in the capacitor During the positive half cycle, if the source voltage is greater than the capacitor voltage the diode will conduct, and the capacitor charges rapidly (C is small) When the capacitor voltage is greater than the input voltage, the diode is reverse-bias: the capacitor will slowly discharge through the load
Diode: Clamping circuit During negative half-cycle, Diode is ‘ON’ The capacitor charges up to During positive half-cycle, Diode is ‘OFF’
Diode: Clamping circuit During positive half-cycle, Diode is ‘OFF’ The capacitor charges up to No charging. Instead, discharging occurs up to
Diode: Clamping circuit During positive half-cycle, Diode is ‘OFF’ The capacitor charges up to No charging. Instead, discharging occurs up to
Diode: Clamping circuit During positive half-cycle, Diode is ‘OFF’ The capacitor charges up to No charging. Instead, discharging occurs up to
Diode: Clamping circuit During positive half-cycle, Diode is ‘OFF’ The capacitor charges up to No charging. Instead, discharging occurs up to
Diode: Clamping circuit During negative half-cycle, Diode is ‘ON’ The capacitor charges up to During positive half-cycle, Diode is ‘OFF’
Diode: Digital logic (Low) (Low) (High) (Low) (Low) (High) (High)
Diode: Digital logic (Low) (Low) (High) (Low) (Low) (High) (High)
Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (High)
Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (High)
Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (Low) (High)
Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (Low) (High)
Diode: Digital logic (Low) (Low) (Low) (High) (Low) (Low) (Low) (High)