ZHCSFD9B July 2016 – October 2018 TPS61230A
PRODUCTION DATA.
For the output capacitor, it is recommended to use small X5R or X7R ceramic capacitors placed as close as possible to the VOUT and GND pins of the IC. If, for any reason, the application requires the use of large capacitors which can not be placed close to the IC, using a smaller ceramic capacitor of 1 µF in parallel to the large one is highly recommended. This small capacitor should be placed as close as possible to the VOUT and GND pins of the IC.
Care must be taken when evaluating a capacitor’s derating under bias. The bias can significantly reduce capacitance. Ceramic capacitors can loss as much as 50% of their capacitance at rated voltage. Therefore, leave margin on the voltage rating to ensure adequate effective capacitance.
The ESR impact on the output ripple must be considered as well, if tantalum or electrolytic capacitors are used. Assuming there is enough capacitance such that the ripple due to the capacitance can be ignored, the ESR needed to limit the VRipple is: