Generally, the capacity of the film capacitors we buy is not exactly the same as the actual nominal capacity. Limited by the current technical level, the actual capacity of the film capacitor will have a certain error with the nominal capacity. For the capacity error of the film capacitor It is usually ±5%, and some are ±10%. Is the capacity error of the film capacitor as small as possible?
Generally, after the film capacitor is produced, its actual capacity will be a little too large and some are too small. The produced capacitor will pass through the sorting machine at the end. The machine can automatically identify the capacity error of the film capacitor. If you want the capacity error to be smaller For thin film capacitors, the sorting machine can be used to automatically select the capacitors that meet the requirements, so that the cost of the manufacturer will become higher, and the price of the capacitor will naturally become more expensive.
From the perspective of price, if the capacity requirements are extremely high, it needs to be selected from mass-produced film capacitors, and its price will naturally be higher. Therefore, from the perspective of cost, it does not mean that the capacity error is greater. Smaller is better.
In fact, many circuits do not have high requirements for the capacitance error of film capacitors. For applications such as bypass, coupling, or low-requirement timing and general delay, you can choose K-range capacitors, that is, film capacitors with 10% tolerance. . For more demanding applications, you can choose a film capacitor with a tolerance of ±5%.
Summary: The capacity error of film capacitors is usually ±5%, which meets the capacity error requirements of most circuits. For circuits with extremely high precision requirements, you can ask the manufacturer to automatically select them through the sorting machine, but the price is slightly more expensive. If the circuit does not require high capacity error, the price of ±10% film capacitors will be lower and cost-effective.