ZERO BIAS

When the base is not connected to anything, or when it is at the same potential as the emitter, a bipolar transistor is at zero bias. Under this condition, which is called cutoff, no appreciable current can flow through a p-n junction unless the forward bias is at least equal to the forward breakover voltage. For silicon, the critical voltage is 0.6 V; for germanium, it is 0.3 V.
With zero bias, the emitter-base (E-B) current IB is zero, and the E-B junction does not conduct. This prevents current from flowing in the collector unless a signal is injected at the base to change the situation. This signal must have a positive polarity for at least part of its cycle, and its peaks must be sufficient to overcome the forward breakover of the E-B junction for at least a portion of the cycle.

مواضيع ذات صلة

الحجم النووي Nuclean Size

ربوتات النانو (Nanorobots)

تلسكوبات الأشعة تحت الحمراء والسينية

المقاومة الداخلية المرتفعة لبطارية ليثيوم-ايون

أهمية تقنية النانو (Importance of nanotechnology)

متسعات المرشح على التوالي Filter Capacitors in series

أشباه الموصلات

ظاهرة الحفز الضوئي

مكشاف أشباه الموصلات Semiconductor detector

ميكروسكوبات السليكون

تأثيرات الدفيئة وثقب طبقة الأوزون

مخطط الطاقة لوصلة ال PN