In applications requiring multiple PGAs, the PGA modules enables the sharing of a common negative sense point (PGA_INM), which leads to less pin usage. This feature is feasible because the PGA_INM pin in the PGA3 module is internally connected to VSSA. To enable this feature, PMUX_SEL must be set to 3. For instance, three PGA modules can be utilized for current measurement in a three-phase inverter with only four pins. The implementation of three-phase current sensing is shown in Figure 2-7. Even though Type-1 PGA supports there-phase low-side current sensing, using Type-2 PGA helps save two pins for other functionality, such as ADC pin and digital inputs and outputs (AGPIO).

Figure 2-7 Three-Phase Current Sensing Using the PGA_NEG_SHARED Feature