Clarification on J7 High-Voltage Measurement Connections in XM3 Three-Phase Inverter

danusha

Dear Team,

I am referring to the XM3 Three-Phase Inverter Reference Design User Guide (PRD-06975), specifically the external high-voltage measurement connector J7 described in Section 2.2.2.

The user guide states that J7 provides three differential high-voltage measurement inputs through six pins:

• Pin 1 – VA-P: Positive HV Measurement Input Phase A
• Pin 2 – VA-M: Negative HV Measurement Input Phase A
• Pin 3 – VB-P: Positive HV Measurement Input Phase B
• Pin 4 – VB-M: Negative HV Measurement Input Phase B
• Pin 5 – VC-P: Positive HV Measurement Input Phase C
• Pin 6 – VC-M: Negative HV Measurement Input Phase C

The guide mentions that the -P and -M inputs are differential inputs and are stepped down by the voltage-sensing circuitry before being provided to the ADC.

I would like to clarify the practical power-stage connections for the three negative measurement terminals VA-M, VB-M, and VC-M.

For a standard three-phase inverter application:

1. Are VA-P, VB-P, and VC-P intended to be connected directly to the respective A, B, and C inverter phase output terminals?
2. Where should VA-M, VB-M, and VC-M be connected?
3. Should all three -M terminals be connected to the mid-point of DC-link?
4. Alternatively, are these inputs intended for line-to-line measurements, for example VA-P → Phase A and VA-M → Phase B?

If possible, could you please provide a wiring diagram or schematic showing the recommended physical connections of all six J7 terminals to the inverter?

Thank you.

~Anusha

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