In a bandgap voltage reference (Widlar topology), the output voltage equals which expression?
AV_BE - 2·V_T only relation
BV_BE + K·VT (cancel TC)
CV_BE·V_T·β always relation
DV_BE / V_T only ratio form
Answer & Solution
Correct answer: B. V_BE + K·VT (cancel TC)
V_BE drops ≈ -2 mV/°C. PTAT voltage K·V_T (V_T = kT/q) rises with T. Choosing K so dV/dT = 0 gives V_ref ≈ 1.25 V, temperature-independent (Widlar 1971).
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