Choose a low resistance precision sensing resistor. If the induction resistor is based on "positioning, positioning, positioning", then choosing a resistor is based on "accuracy, precision, precision" when selecting a sensing amplifier chip. When a voltage with a resistance less than 1 ohm is sensed, small changes in voltage can have a significant induction effect. The sensing amplifier amplifies voltage changes to make the "position, position, position" of the unimportant but important sensing resistors. This refers to sensing at the power source, known as high voltage side sensing, or sensing at the ground connection, known as low voltage side sensing. The application of precision current sensing is no longer starting from scratch, and manufacturers of Hall effect sensors have completed all the research and most of the work for modern designers.

Select sampling resistor

The choice of resistance value, accuracy, and physical size depends on the expected measured current. The larger the resistance value, the more accurate the measurement may be, but the larger the resistance value, the greater the current loss. For low-power battery powered equipment that must reduce losses, resistors with a length of about one millimeter and a value of one percent or several thousand ohms are usually used. For higher currents of one ampere or more, larger resistors can be used to achieve more accurate measurements with acceptable losses. The selection of Hall effect sensors is different from the pursuit of sampling resistors, and the key consideration is accuracy. The following article will compare the differences in selection techniques between the two.