What are the selection criteria for resistors in circuit design?

The selection criteria for resistors in circuit design mainly include the following aspects:

Resistance value: Determine the required resistance value according to the circuit design requirements, and consider the nominal resistance value and allowable error when selecting. The calculation of resistance value is usually based on the current and voltage requirements of the circuit.

Power: The power of the resistor should be sufficient to withstand the current and voltage passing through it. Generally, a resistor with a rated power twice higher than the actual power consumption is selected to ensure long-term stable operation.

Accuracy: The accuracy of a resistor represents the deviation between its actual resistance value and the nominal resistance value. High precision circuits require the selection of high-precision resistors. Common accuracy levels include 0.1%, 1%, 5%, etc.

Temperature coefficient: The resistance value of a resistor will change with temperature. Choosing a resistor with a smaller temperature coefficient can improve the stability and reliability of the circuit, especially in environments with large temperature changes.

Packaging type: The packaging type of a resistor determines its installation method and usage environment in the circuit. Common packaging types include patch and plug-in, and the selection should consider the space and layout requirements of the circuit board.

Work environment: Choose the appropriate type and material based on the working environment of the resistor. For example, high temperature resistant resistors should be selected when close to heat sources, and resistors with good moisture resistance should be selected in environments with high humidity.

Cost and procurement risk: Under the premise of meeting technical requirements, cost-effective resistors should be selected, and the availability of components and supply chain stability should be considered.

Reliability: Choosing well-known brands and certified products can improve the reliability of circuits and ensure that resistors maintain stable performance over long-term use.