A Precision Microcurrent Source for Testing Sensors in New Energy Vehicles

With the rapid development of new energy vehicle industry, the performance and reliability of in-vehicle sensors have become increasingly critical. Microcurrent sources serve as essential equipment for calibrating and testing these highly sensitive sensors. Their output accuracy, stability and anti-interference ability directly determine the credibility of calibration and testing results. To address the current challenge of lacking traceable standard for microcurrent at 0.1 mA and below in microcurrent equipment used for testing sensors in new energy vehicles, this paper designed a high-precision, low-noise and anti-interference precision microcurrent source. By overcoming three core challenges including precision microcurrent generation technology, negative feedback amplification and measurement technology for microcurrent signals, noise signal suppression and control technology, this microcurrent source achieved a stable output of microcurrent ranging from 0.2 pA to 20 mA. For this microcurrent source, we established a test verification system, analyzed the sources of uncertainty in the verification process, and conducted an uncertainty assessment. The results validated that the microcurrent source demonstrated reliable performance and met the technical requirements.