Explanation: pnp transistors in Integrated Circuits are fabricated in one of the following three ways. 9. State the correct reason for neglecting pnp transistor.
A. Increase in the series collector resistance of pnp transistor
B. Parasitic capacitance appears between collector and substrate
C. Current gain of pnp transistor is as low as 1.5 to 30
D. None of the mentioned
Answer:A
Explanation: pnp transistors in Integrated Circuits are fabricated in one of the following three ways. 9. State the correct reason for neglecting pnp transistor.
A. Increase in the series collector resistance of pnp transistor B. Parasitic capacitance appears between collector and substrate C. Current gain of pnp transistor is as low as 1.5 to 30 D. None of the mentioned
Explanation: Lateral pnp transistor has inferior characteristic as the base width is usually larger controlled by lateral diffusion of p-type impurities and photographic limitations during mask marking and alignment. Therefore, pnp transistor normally gives current gain as low as 1.5 to 30 compared to 50-300 for the npn transistor. 10. The diffusion of collector impurities in npn transistor should be small because,