SLUU274A May 2007 – January 2022 TPS40193
The TPS40193EVM-001 has three test points and a local ground connection (TP7) to monitor the main switching waveforms. Connect an oscilloscope probe to TP8 to monitor the high-side gate drive applied to the gate of Q2. Connect an oscilloscope probe to TP9 to monitor the switch node voltage. The gate-to-source voltage (VGS) of the high-side FET can be determined by a math function TP8—TP9 if both channels use the same scale. Connect an oscilloscope probe to TP9 to monitor the low-side gate drive applied to the gate of Q3. Because the source of Q3 is connected directly to ground, no math function is required to determine the gate-to-source voltage of the low-side FET.