35 V rated — the derating decision
The TAJC106M035Y: The 35 V rated voltage sets the derating floor: for a tantalum capacitor, the standard practice is to run at no more than two-thirds of the rated voltage, so a 35 V part is suitable for rails up to about 23 VDC continuous. The ±20% tolerance on the 10 µF capacitance is typical for tantalum; the actual value at the operating voltage and temperature will be lower than the nominal, so budget the capacitance drop into the ripple calculation.
1.6 Ohm ESR and the thermal budget
The 1.6 Ohm ESR at 25 °C determines the ripple current rating and self-heating. In a 35 V bulk decoupling application, the ESR contributes to the output ripple voltage; the power dissipation is I²R, so a 200 mA ripple current produces about 64 mW of heat inside the molded case.