SLUAB09 October 2025 AMC0386-Q1 , TPS61170 , TPS61170-Q1 , TPSI2140-Q1
As adoption of electric vehicles accelerates, bidirectional onboard chargers (OBCs) with V2X capability have become essential. System?level analysis shows that neither an AC?side residual?current device (RCD), nor a DC?side insulation monitoring device (IMD) located in the BMS, can satisfy the insulation monitoring demands of V2X operations. By examining the V2X requirements for OBCs and the fundamentals of conventional DC?IMD, this document introduced three viable AC?IMD topologies and evaluated the advantages and compromises of those topologies using the included calculations.
The basic architecture currently provides a lower cost option, but the performance of the architecture is limited. The dual-switch architecture provides the highest performance at a cost that is currently comparatively higher. The active single-switch architecture requires an external power supply, but currently offers the better balance between performance and cost.
Integrating these detection schemes with an appropriate solid?state?relay device offered by TI enables designers to achieve an excellent balance of accuracy, speed detection, footprint, and reliability for V2X?enabled OBCs.