⚙️ Power Electronics & Integrated Circuits

Session 5: IGBT & IC Technologies

⚡

Insulated Gate Bipolar Transistor (IGBT)

Combines advantages of BJT and MOSFET

Structure & Terminals ▼

Layers: Emitter (N+ Layer) → Base (P-Layer) → Collector (N+ Layer) → Gate (Insulated)

Terminals: Emitter (E), Gate (G), Collector (C)

Operation Modes ▼

Off State: V_GE < V_th - Only small leakage current flows

On State: V_GE > V_th - Large current flows from collector to emitter

Saturation: Fully on with minimal voltage drop

Key Characteristics

  • Voltage-controlled like MOSFET
  • High current handling like BJT
  • Fast switching (but slower than MOSFET)
  • Low on-state voltage drop
  • High voltage rating (up to 6.5kV)
  • Moderate switching losses

✓ Advantages

  • High efficiency in power conversion
  • Can handle high voltage and current
  • Lower switching losses than BJT
  • Better thermal stability

⚠ Disadvantages

  • Slower switching than MOSFET
  • Complex gate drive required
  • Higher cost than BJT/MOSFET
  • Latch-up issues possible

🚗 Applications in Electric Vehicles

1. Motor Drive Inverters
Convert DC from battery to AC for motor
💡 Critical for propulsion efficiency
2. DC-DC Converters
Step voltage for auxiliary systems
💡 Powers 12V systems from high-voltage battery
3. On-board Chargers
AC-DC conversion for battery charging
💡 Enables fast and efficient charging
4. Regenerative Braking
Manages recovered energy flow
💡 Increases driving range
📈

Analog Integrated Circuits

Process continuous signals

Types of Analog ICs

Op-Amps
Voltage Regulators
ADC
Comparators
Timer ICs

Key Characteristics

  • Handle continuous voltage/current
  • Linear signal processing
  • High precision required
  • Sensitive to noise

🚗 Applications in Electric Vehicles

1. Battery Voltage Monitoring
Precision voltage measurement of cells
💡 Ensures battery safety and longevity
2. Current Sensing
Monitor charging/discharging currents
💡 Protects against overcurrent
3. Temperature Sensing
Battery and motor temperature monitoring
💡 Thermal management and safety
4. Sensor Signal Conditioning
Process signals from various sensors
💡 Accurate vehicle control and safety
💻

Digital Integrated Circuits

Process discrete binary signals

Types of Digital ICs

Microprocessors
Microcontrollers
Memory (RAM/ROM)
Logic Gates
DSP

Key Characteristics

  • Handle binary data (0s and 1s)
  • Digital signal processing
  • High noise immunity
  • Programmable functionality

🚗 Applications in Electric Vehicles

1. Battery Management System
Control logic and cell balancing
💡 Optimizes battery performance
2. Motor Control Unit
Precise motor speed and torque control
💡 Smooth acceleration and efficiency
3. Vehicle Control Unit
Central vehicle coordination
💡 Integrates all EV subsystems
4. ADAS Systems
Process sensor data for safety features
💡 Collision avoidance, lane keeping
🔀

Mixed-Signal Integrated Circuits

Combine analog and digital functions

Types of Mixed-Signal ICs

ADC
DAC
Mixed MCU
SoC

Key Characteristics

  • Bridge between analog and digital
  • High integration
  • Complex design
  • Versatile functionality

🚗 Applications in Electric Vehicles

1. Battery Monitoring ICs
Convert analog voltages to digital data
💡 Accurate state-of-charge calculation
2. Motor Drive ICs
Digital control with analog power output
💡 Efficient motor operation
3. Power Management ICs
Regulate and distribute power
💡 System efficiency and protection
4. Communication Interfaces
CAN, LIN bus transceivers
💡 Vehicle network communication

BJT vs MOSFET vs IGBT Comparison

Feature BJT MOSFET IGBT
Control Type Current Voltage Voltage
Switching Speed Slow Very Fast Fast
Voltage Rating Low-Medium Medium Very High
Current Capability Medium Medium Very High
On-State Loss Low Very Low Low
Best EV Use Signal circuits DC-DC converters Motor inverters

* Highlighted cells indicate best-in-class performance for EV power electronics

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