In a traction inverter, IGBT module temperature is commonly monitored using an NTC resistor embedded near the power switch or baseplate. The NTC forms a temperature-dependent voltage (typically through a bias and pull-up network) that is digitized by an ADC located in the inverter power domain, close to the sensing point. Placing the ADC near the IGBT/NTC minimizes analog trace length, improves immunity to high dV/dt switching noise, and helps preserve measurement accuracy in the electrically harsh inverter environment. The ADC communicates the conversion results to the main inverter controller over I2C, but the ADC side is referenced to a local ground that can shift relative to the MCU logic ground due to switching currents and ground bounce.

As shown in Figure 3-8, the TXG8122-Q1 is inserted in the I2C path to provide bidirectional SDA/SCL level translation and ground-domain re-referencing. With VCCA/GNDA tied to the MCU domain and VCCB/GNDB tied to the ADC domain, TXG8122-Q1 maintains compliant logic thresholds and improves noise margin across the interface, enabling robust temperature telemetry from the IGBT NTC sensing network without requiring galvanic isolation.