Laboratory courses for upper-division undergraduates often involve sophisticated equipment, relatively small class sizes, and extended hands-on projects. These courses present distinct challenges and opportunities for the physics education research community as these features are not often present in other undergraduate courses. Here, we focus on an upper-division lab-based electronics course. As a first step in establishing learning goals for upper-division electronics, we interviewed graduate students and faculty at the University of Colorado Boulder about the use of electronics in their own research labs. The content-specific nature of electronics courses parallels the hands-on experience of graduate student researchers, so focusing on the experiences of graduate students is ideal for informing lab course reform. From their interview responses, we developed a framework for classifying applications of electronics. We identify five types of use and four forms of interaction with electronics content that are consistently identified by faculty and graduate students. However, we see variations between faculty and graduate students regarding how electronics is learned.