BC556B PNP Transistor Common-Emitter Output Curve Tracer

Application

This circuit shows BC556B PNP Transistor in a common-emitter curve-tracer setup. It is useful when comparing collector-current capability, saturation behavior, and the effect of base drive before choosing bias or load values.

Design Context

The emitter-collector voltage source sweeps VEC from 0 V to 10 V. A secondary DC sweep steps the emitter-base drive source from 0.65 V to 0.8 V through RB, creating a family of collector-current curves from one schematic. Pin behavior should be reviewed in the component editor.

Expected Behavior

Collector current magnitude increases as emitter-base drive increases. At low VEC the curves show the saturation knee; at higher VEC they flatten into the active region where the transistor behaves more like a controlled current device.

Key Values

• VEC sweep: 0 V to 10 V in 0.1 V steps.
• VEB sweep: 0.65 V to 0.8 V in 0.05 V steps through RB.
• RB: 220 kOhm, providing modest base-drive current for small-signal characterization.

Suggested Experiments

• Reduce RB to increase base drive and compare the collector-current curves.
• Narrow the VEC sweep around 0 V to 1 V to inspect saturation behavior more closely.
• Change the VEB step range to focus on lower-current or higher-current operation.

Featured Component

BC556B PNP Transistor is the PNP transistor under test. Its collector, base, and emitter terminals are arranged in a common-emitter characterization setup so the chart emphasizes output-current behavior versus emitter-collector voltage.