SBVS343A March 2019 – September 2019 TPS7A78
The TPS7A78 can be configured to operate either in full-bridge (FB) or half-bridge (HB) configurations. HB configuration ties the AC input pin without the series CS and RS components to the device GND pins. See Figure 14 and Figure 15 for the HB and FB configurations.
When FB configuration is used, do not tie the device GNDs to earth GND neither schematically nor accidentally via an earth-grounded oscilloscope or measurement equipment because the device GNDs and earth GND are at different voltage potentials. Doing so and can cause damage to the device and external equipment. Tying the device GND pins to earth GND when FB configuration is used is only acceptable if a second surge resistor RS is used on the AC input pin side without the series CS and first RS, as illustrated in Figure 16 with floating device GND pins and Figure 17 with non-floating (earth grounded) device GND pins.