Resistance measurement module and measurement method

Abstract

The invention aims to provide the resistance measurement module and the measurement method which can effectively eliminate the influence of circuit bias, can quickly judge the reason of poor contact and are high in measurement precision. The circuit comprises a DAC module, a voltage source module, an E-load and current sampling module, a voltage sampling module and an ADC module, and the DAC module controls the voltage source module to output a specified voltage and controls the E-load and current sampling module to provide currents of different gears. The E-load, the current sampling module and the voltage sampling module feed back a sampling result to the ADC module for analysis and processing; the voltage sampling module acquires the connection state of a resistor to be measured while performing voltage sampling so as to quickly judge and eliminate the error measurement problem, and an accurate resistance value is acquired by making a difference between measurement values of two tests so as to eliminate errors caused by bias voltage. The module and the method are applied to the technical field of resistance measurement.

Description

technical field [0001] The invention is applied to the technical field of resistance measurement, and in particular relates to a resistance measurement module and a measurement method. Background technique [0002] With the rapid improvement of the quality of life and the rapid progress of science and technology, all kinds of electronic products emerge in an endless stream. Resistors, as the most common electronic components, play the most common and important role in various circuit designs. In some special systems, such as high-power circuits, current measurement, signal acquisition, etc., the accuracy of the resistance directly affects the stability and accuracy of the entire system. At present, in the production process of electronic products, the first step in the functional quality inspection of the product is to measure the resistance to ensure that the product has no open circuit or short circuit and can be powered on normally. Therefore, resistance measurement is u...

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Problems solved by technology

[0004] Existing equipment or standard function boards can meet the resistance test requirements of various precision and range, but for the problem of mismeasurement of small resistance caused by poor contact in the test system, there are certain deficiencies in the processing of function boards, mainly as follows Point: During the four-wire small resistance test, a signal of the voltage sampling is not connected properly due to poor contact. At this time, the output voltage on the sampling circuit is floating, and there is a certain probability that the measurement result of the sampling circuit is close to the theoretical value. This will lead to false detection; some existing designs will add up / down resistors to the sampling circuit, so that the sampling circuit will output high or low levels when the signal is in poor contact, but the noise of the up / down resistors and the up / down power supply will cause There is a certain error in the normal test results; in the environment where space is limited and functional boards are required, the resistance of the pull-up and pull-down resistors is often increased to reduce the measurement error, but it cannot be eliminated

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