An Electronic-Circuit Platform for Comprehensive PSpice Simulation and PCB Troubleshooting

In this paper, we present an electronic circuit platform to educate students to further develop research skills via PSpice and PCB troubleshooting. Stemming from an externally funded undergraduate project, the electronic circuit platform is part of a science payload to measure the energy of cosmic-rays in near space on a high-altitude balloon flight. The payload for the energy measurement consists of the Data Collection Module (DCM), the Trigger Logic Module (TLM), and the Data Management Unit (DMU). The DCM is further composed of the Integrator Module (IM) and the Peak Detector Module (PDM). The PDM consists of 25 channels of a well-known peak detector and the IM consists of 30 channels of multi-stage electronic circuits for processing of the analog signals from 30 Silicon Photomultipliers (SiPMs). Each IM channel is composed of a trans-impedance amplifier, a trans-conductance amplifier, and an integrator as well as one comparator for generation of an integration-control signal at the input stage of the integrator and another comparator for generation of digital signals at the output stage of the integrator. All of these IM circuits employ an Operational Amplifier (OP Amp) that an electronics course in electrical engineering (EE) covers typically at the sophomore level. These 30 channels of electronic circuits are implemented on 8 printed circuit boards (PCBs) each processing 4 channels. Referring to the four-channel PCB as the electronic-circuit platform in this paper, we identify several challenges that typical EE students would face – 1) Each channel has five OP Amp stages which present significantly more complexity than what students learned from their coursework for dc biasing and ac analysis; 2) These OP Amps operate at a much higher frequency than the typical OP Amps such as LM 741 used in their coursework. That is, the SiPM signal duration of interest is 1 μs ~3 μs (e.g., 300 kHz~ 1 MHz signal) while the OP Amp used in classroom typically operate at a few kHz; 3) The common ground for all four channels quite often present performance issues with parasitic effect between channels on dc biasing and ac signal processing. A proper grounding for electronic circuits is one of the known challenges to undergraduate students. Beyond the importance of the proper initial circuit design, when the constructed PCB experiences problems, successful troubleshooting of the electronic-circuit platform can be best facilitated with the use of both PSpice simulation and PCB troubleshooting. Proper logging of observations and experimental data determines the course of action during the troubleshooting. In this paper, we present concise but sufficiently detailed PSpice implementation and PCB board design, technical issues encountered, and the methodology to troubleshoot the circuit, illustrating how to promote both circuit analysis and experimental verification utilizing both PSpice and PCB.