Nominal capacitance value of capacitor
Hi Electronics Enthusiasts,
I have some IC which is working in 3.3V supply. For this IC, I need an effective capacitance 3uF according to the rough calculation using this equation [c=i×del_t/del_v]. So I'm select nominal capacitance as 10uF with voltage rating of 10V. In environmental conditions, a capacitance can change in voltage and also temperature. The change of capacitance, it doesn't meet minimum effective capacitance. For this case what can I do? This is also applicable for recommended capacitance in a datasheet.
Hi Balaji, for this kind of some how strict conditions I normally follow the next rules:
1.- the voltage rating of the capacitors: always at least 30% more than the maximum voltage that you will have. your rated voltage of 10V satisfies this.
2.- use NP0/COG capacitors, with 1% of tolerance over the range of temperatures.
3.- If you decide to use 10uF, try 2x4.7uF in parallel. With this you have les ERS which means less ripple and less variation of the total capacitance over the temperature conditions.
Hope it helps
Ignasi