TPS7A90 datasheet(SBVS324) recommends to use ceramic capacitors of 10uF or greater at the input and output.
And there is also the below description on 8.1.3 Capacitor Recommendation.
“The TPS7A90 is designed to be stable using low equivalent series resistance (ESR) ceramic capacitors at the
input, output, and noise-reduction pin. Multilayer ceramic capacitors are the industry standard for these types of
applications and are recommended, but must be used with good understanding of their limitations. Ceramic
capacitors that employ X7R-, X5R-, and COG-rated dielectric materials provide relatively good capacitive stability
across temperature, whereas the use of Y5V-rated capacitors is discouraged precisely because the capacitance
varies so widely. In all cases, ceramic capacitors vary a great deal with operating voltage and temperature and
the design engineer must be aware of these characteristics. As a rule of thumb, ceramic capacitors are
recommended to be derated by 50%. The input and output capacitors recommended herein account for a
capacitance derating of 50%.”
So does that mean user can use 10uF with X7R, X5R or COG rated?
Or does that mean user should use 15uF with X7R, X5R or COG rated?
I also have another question.
Where does this 10uF for both input and output come from? My customer feels it is a little bit large capacitor.
Would it cause unstable issue if using less than 10uF?