Analysis of High Value Resistor Selection for Trans impedance Amplifier of Weak Current Measurement

Weak current detection is widely used in many fields such as biomedicine, chip testing, and magnetic field detection. The commonly used methods for weak current detection mainly include shunt detection and transimpedance amplification. Transimpedance amplification is often used for weak current detection at the nanoampere level and below. High-value resistors are the core components of transimpedance amplifier circuits, and their selection has a significant impact on the performance of the amplification circuit. The material and package method of the resistors have an impact on weak current detection, which is difficult to intuitively measure from the indicators given in datasheets. This paper aims to compare and analyze through experiments the stability and minimum detectable current electrical characteristics of high-value resistors of various materials and mounting methods in current detection, to determine the suitable high-value resistor materials and mounting methods for weak current detection at the set range, and to provide some suggestions for high-value resistor selection.