Main parameters of resistors and capacitors - News - Global IC Trade Starts Here Free Products

SMD aluminum electrolytic capacitor

Brand AVX TPSE226M035R0125 Low impedance tantalum capacitor AVX 22

Chip ceramic capacitor

Tantalum capacitor

The main electrical parameters of a resistor include the following: 1) Nominal resistance and tolerance: This refers to the expected value of resistance and the allowable deviation from that value. 2) Rated power: The maximum power the resistor can dissipate without damage. 3) Maximum working voltage: The highest voltage it can handle safely. 4) Noise electromotive force: The internal noise generated by the resistor, which can affect signal integrity in sensitive circuits. 5) Temperature coefficient: How much the resistance changes with temperature. A lower coefficient means better stability. For capacitors, the key characteristic parameters are as follows: (1) Capacity and error: This is the difference between the actual capacitance and the nominal value. Capacitors are typically divided into three grades: I (±5%), II (±10%), III (±20%). Some may have a grade 0 with ±20% tolerance. Precision capacitors have tighter tolerances, while electrolytic capacitors tend to have larger errors. The accuracy is often marked with letters, such as D (±0.5%), F (±1%), G (±2%), J (±5%), K (±10%), and M (±20%). (2) Rated working voltage: The maximum DC voltage the capacitor can withstand over time without failure. Higher voltage ratings usually mean larger physical size for similar construction and capacitance. (3) Temperature coefficient: The change in capacitance per degree Celsius. A smaller coefficient is preferable for stable performance. (4) Insulation resistance: Indicates the leakage current through the dielectric. Small capacitors typically have high insulation resistance (hundreds of megaohms or even gigaohms), while electrolytic capacitors have lower values. Higher insulation resistance means less leakage. (5) Loss: Energy lost as heat due to dielectric and conductor losses. It's often expressed as the loss tangent, which helps evaluate efficiency. (6) Frequency characteristics: How the capacitor behaves at different frequencies. At higher frequencies, the dielectric constant decreases, reducing the effective capacitance and increasing losses. Other factors like lead inductance and internal resistance also play a role, limiting the usable frequency range. Different types of capacitors have varying maximum operating frequencies—for example, mica capacitors up to 250 MHz, ceramic capacitors up to 3000 MHz, and paper capacitors up to 80 MHz. When using aluminum electrolytic capacitors, consider the following: 1. They must be used in DC circuits, with clear polarity markings. 2. If the circuit polarity is uncertain, use non-polar electrolytic capacitors. 3. Avoid exceeding the specified operating temperature range. 4. Store them in cool, dry places. If stored long-term, apply rated voltage before use. 5. Ensure ripple current stays within limits; choose high-ripple-capable capacitors if needed. 6. Do not exceed the rated voltage during operation. 7. Keep heat sources like soldering irons away from the plastic casing to prevent damage. 8. Limit soldering time to 10 seconds and temperature to 260°C. 9. Avoid applying excessive force to the leads or terminals, as this can damage internal components.