SPRAD58B September   2022  – February 2026 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1 , UCC14130-Q1 , UCC14131-Q1 , UCC14140-Q1 , UCC14141-Q1 , UCC14240-Q1 , UCC14241-Q1 , UCC14340-Q1 , UCC14341-Q1 , UCC15240-Q1 , UCC15241-Q1 , UCC5870-Q1 , UCC5871-Q1 , UCC5880-Q1 , UCC5881-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Architectures and Trends
    1. 2.1 Two-Level and Three-Level Inverters
    2. 2.2 E-Axles and X-in-1 Architecture
    3. 2.3 Other Trends in Traction Inverter Design
  6. 3 Key Technology to Enable Traction Inverters
  7. 4 Microcontroller and Power Management IC
    1. 4.1 C2000™ Family
    2. 4.2 Power Management IC
  8. 5 Isolated Gate Drivers
  9. 6 Low Voltage Isolated Bias Supply
  10. 7 High Voltage Isolated Bias Supply
  11. 8 DC Link Active Discharge
  12. 9 Motor Position Sensing
  13. 10Isolated Voltage and Current Sensing
    1. 10.1 Isolated Current Sensing
    2. 10.2 Isolated Voltage Sensing
  14. 11System Engineering and Reference Designs
  15. 12Conclusion
  16. 13References

2.2 E-Axles and X-in-1 Architecture

One example of improving system level integration is the implementation of E-Axles, which combine the power electronics, electric motor, and transmission into one housing. E-Axles improve motor performance by achieving higher torque and top speed, while improved cooling and a coil winding structure increase power density and motor efficiency. E-Axles are already common today and can be found on both front and rear axle drives, as well as in dual motor vehicles.

Integration can be extended to additional parts of the electric powertrain. This enables the rise of the X-in-1 system integration trend, which combines even more powertrain components to potentially improve size, cost, efficiency and weight. There is no standard combination for X-in-1 designs. In general, the components in Table 2-1 can be combined up to a 12-in-1 level.

Table 2-1 Different Levels of Component Integration in the Electric Powertrain
ComponentX-in-1 Design Name
E-Motor3-in-1 (E-Axle)6-in-18-in-112-in-1
Inverter
Gearbox
Onboard Charger (OBC)
HV DC-DC Converter
Power Distribution Unit (PDU)
Vehicle Control Unit (VCU)
Battery Management System (BMS)
Starter Generator
Intelligent Boost Modules
Thermal Management
Positive Temperature Coefficient (PTC)

For any of these X-in-1 levels, in general, three different strategies can be observed (see Table 2-2):

  1. X-in-1 in the box: Combines different component boards into one box.
  2. X-in-1 on the board: Combines functionalities onto one board.
  3. X-in-1 in the device: Combines functionalities into one MCU.
Table 2-2 Design Strategies for X-in-1 Integration
Integration FactorOne BoxOne BoardOne Chip
ScalabilityHigh – each function has a specific PCBLow scalability
Load SharingLess loading – each MCU focuses on real-time tasks without overloadingShared work across MCUsHigh loading – MCU handles many real-time tasks at the same time
SafetyMust always be achieved
AvailabilityIndependently operatingBetween one board and one chip designNo availability if fault in common component (MCU, PMIC, and so forth)
LayoutEasier to layoutHard to layout, thermal and EMC concerns
SoftwareLess complexityHigh complexity
HeatMultiple spots distributing heatSingle heat spot can require active cooling
ResourcesScalable using different processor componentsNeeds cascaded design
CommunicationRequires cables, connectors, PHYsNo cables, connectors, or PHYs needed
Resource ExpansionNo GPIO expander neededPotentially requires GPIO expanderFixed resources and pin count can require additional logic
Design WeightHigh – due to multiple boards and wiringLow
Design SizeHighest volume (stacked boards)Single board design for low height

The 8-in-1 architecture dominated the market in 2025. Still, from 2030 onward, 12-in-1 integration is expected to take a significant amount of share alongside the lesser-advanced 6-in-1 integration version. As of today, integration is largely driven from China.