LD1117S50 output capacitor

[GKris.1]

Hi, We are using LD1117S50 linear regulator for conversion of 9V DC to 5V DC. The datasheet typical application diagram in page 24 suggests to use 10uF electrolytic capacitor. Please let me know whether we can use a 10uF ceramic capacitor at output. Will there be any issues if we use a ceramic 10uF at output instead the Electrolytic one.

Thanks,

Gopi Krishnan K.

[Peter BENSCH · Accepted solution]

The LD1117 is a so called Quasi-LDO requiring an output capacitor with a value of at least 10µF and an ESR of >0.25 ohms, even it is not stated in the datasheet.

Ceramic capacitors providing very low ESR can be used with an artificial ESR, i.e. if you connect a resistor of e.g. 1 ohm in series.

Alternatively you could also use a tantalum cap.

Does it answer your question?

/Peter