Understanding of Surface mount Resistors

Surface mount components have the advantages of small size, light weight, high installation density, strong earthquake resistance, strong anti-interference ability, and good high-frequency characteristics. They are widely used in computers, mobile phones, electronic dictionaries, medical electronic products, cameras, electronic meters, and VCD players. Surface mount components can be classified into three types based on their shape: rectangular, cylindrical, and irregular. Divided by type, there are resistors, capacitors, inductors, transistors, and small integrated circuits. The nominal method of surface mount components is different from that of general components. The following mainly discusses the nominal resistance method of chip resistors.diode

The resistance value of a chip resistor is the same as that of a general resistor, and is indicated on the resistor body. There are three methods for nominal resistance value, but the nominal method is not exactly the same as that of a general resistor.diode

1. Digital positioning nominal method (generally used for rectangular sheet resistors)

The numerical indexing method is to use three digits on the resistor body to indicate its resistance value. Its first and second digits are significant digits, and the third digit represents the number of zeros added after the significant digits. This digit does not contain any letters.diode

For example, '472' represents' 4700 Ω '; 151 "represents" 1500 ".

If it is a decimal, use "R" to represent the "decimal point" and occupy one significant digit, while the remaining two digits are significant digits.

For example, "2R4" represents "2.4 Ω"; R15 "represents" 0.15 Ω ".diode