TIDUF18A October 2022 – February 2024
The Hall-effect sensor ACS733KLATR-40AB-T is used for the total input current sensing, as Figure 3-10 shows. The OPA320-based amplifier circuit tunes the low output voltage of the sensor to a higher level and sends this voltage to the controller ADC pin. The ACS733KLATR-40AB-T device senses each individual interleaved phase's current which allows phase current balancing.
The output voltage from the signal conditioning circuit is scaled to match the ADC range using the circuit as shown in Figure 3-9. The voltage is calculated as:
The input AC voltage is sensed differentially by sensing the line, and the neutral inputs refer to the control ground separately with two voltage dividers, as Figure 3-11 shows. The control ground is the DC link negative terminal; therefore, a single voltage divider can be used to sense the DC bus voltage. An RC filter filters the signals before connecting to the controller. A common RC filter is used for all the sensing signals on this design.