page_title: Common emitter
hierarchical_section_title: Common emitter
context_page_description: In electronics, a common-emitter amplifier is one of three basic single-stage bipolar-junction-transistor amplifier topologies, typically used as the voltage amplifier.
  In this circuit the base terminal of the transistor serves as the input, the collector is the output, and the emitter is common to both, hence its name. The analogous FET circuit is the common-source amplifier, and the analogous tube circuit is the common-cathode amplifier.
context_section_description: In electronics, a common-emitter amplifier is one of three basic single-stage bipolar-junction-transistor (BJT) amplifier topologies, typically used as the voltage amplifier.
  In this circuit the base terminal of the transistor serves as the input, the collector is the output, and the emitter is common to both (for example, it may be tied to ground reference or a power supply rail), hence its name. The analogous FET circuit is the common-source amplifier, and the analogous tube circuit is the common-cathode amplifier.
caption: Figure 1: Basic NPN common-emitter circuit (neglecting biasing details)