Some diode V-I curve
fllower is TL431 in all current range V-I curve
if you plug TL431 into socket B and E,and change the measure condition,you can see less current VI curve. The following figure , Y-axis is only 0~0.38mA
the Intelligent Curve Tracer is more powerful,It can measure 3 terminal voltage regulator’s Vi-Vo / Io-Vo Curve