Datasheet notation: The small-signal common-emitter current gain denoted by hfe (lowercase h, f, e) corresponds to which familiar transistor parameter?

Introduction:
Transistor datasheets use the h-parameter model for small-signal behavior, where symbols like hfe, hie, and hoe appear frequently. Knowing how these map to everyday terms such as beta (β) avoids confusion when comparing devices or calculating bias and gain.

Given Data / Assumptions:

• BJT characterized in common-emitter configuration.
• Small-signal linearization around a bias point.
• Standard h-parameter notation is used.

Concept / Approach:
In the hybrid h-parameter set for a common-emitter amplifier, hfe is the small-signal forward current gain, essentially ΔIC / ΔIB at a given operating point. This is the same quantity commonly called beta (β). While β can also denote DC current gain (sometimes labeled hFE with uppercase FE), hfe (lowercase) refers to incremental (small-signal) gain; context in datasheets usually makes the distinction clear.

Step-by-Step Solution:
Identify symbol: hfe.Match to definition: small-signal forward current gain in common-emitter.Map to familiar term: beta (β), i.e., change in collector current per change in base current.Note practical ranges: β may vary widely with device, current, and temperature.

Verification / Alternative check:
Consult any BJT datasheet: parameters listed as hfe or hFE correspond to current gain figures; test conditions specify collector current and VCE, confirming the mapping to β.

Why Other Options Are Wrong:
Alpha: equals IC / IE in common-base, not CE current gain.Hi-fi: unrelated slang for audio quality.Transconductance gm: equals ΔIC / ΔVBE and has units of siemens, not a unitless current ratio.

Common Pitfalls:
Confusing hfe (small-signal) with hFE (DC). Both are forms of β but measured differently; design calculations must match the appropriate definition.

Final Answer:
beta (common-emitter current gain)