As shown in Figure 2-1, use a ceramic bypass capacitor, C_BYPS, with a minimum capacitance of 10 μF. The voltage rating must be taken into consideration because this capacitor will experience stress equal to the full voltage range between V_IN and V_OUT.

For the system to be stable, there must be an input power supply capacitor to help dampen the high-frequency noise that can couple onto the circuit. An electrolytic capacitor with moderate ESR helps dampen any input supply ringing caused by long power leads. When using the TPSM63610EVM, C_BULK capacitor must be added across V_IN and SYS_GND.

Consider that the inclusion of the C_BYPS capacitor introduces an AC path from V_IN to V_OUT and might worsen the transient response. When V_IN is applied to the circuit, this dV/dt across the bypass capacitor creates a current that must return to ground to complete the loop. This current might flow through the internal low-side body diode of the MOSFET and the inductor to return to ground. For this case, it is recommended to have a Schottky diode between -V_OUT and SYS GND. If large line transients are expected, increase the output capacitance to keep the output voltage within acceptable levels.

Figure 2-1 TPSM63610 Inverting Buck-Boost Schematic