0
\$\begingroup\$

I want to use MIC29302 as regulator in SIM800L circuit.

In the suggested circuit in the datasheet there is a 100 µF capacitor before the regulator and a 330 µF capacitor after the regulator, but there is no information about the voltage of these capacitors in it.

How should I choose the appropriate capacitors?

\$\endgroup\$
0
\$\begingroup\$

The datasheet states:

This capacitor need not be an expensive low ESR type: aluminum electrolytics are adequate. In fact, extremely low ESR capacitors may contribute to instability. Tantalum capacitors are recommended for systems where fast load transient response is important. Where the regulator is powered from a source with high AC impedance, a 0.1 μF capacitor connected between Input and GND is recommended. This capacitor should have good characteristics to above 250 kHz.

The voltage rating of the capacitors depend the maximum possible (peak) voltage they can encounter. Pick a voltage rating 1.25 times (elco) to 2 times (tantalum) the highest (peak) voltage the capacitor will see.

I'd go for safe if price and/or size don't matter, so, e.g. a 50V rating for the output.

\$\endgroup\$
  • \$\begingroup\$ Can i use a 50V for input too? \$\endgroup\$ – Fariborz Dehghani Sep 9 '19 at 7:03
  • \$\begingroup\$ @FariborzDehghani That depends on the input voltage and possible peaks on it \$\endgroup\$ – Huisman Sep 9 '19 at 18:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.