Question

Why do zener breakdown voltage has a negative temperature coefficient whereas the avalanche breakdown voltage has a positive?

Answer 1

Explanation:

zener breakdown has negative temperature coefficient means if temperature increases then breakdown voltage decreases and opposite in avalanche breakdown

Zener breakdown and temperature effect: ... As temperature increases , band gap decreases so less electric field is required to torn electrons from valence band to conduction band. So zener breakdown voltage decreases as the temperature increases. Thus zener breakdown is negative temperature coefficient.

Answer 2

Explanation:

The main difference between Zener breakdown and avalanche breakdown is their mechanism of occurrence. Zener breakdown occurs because of the high electric field whereas, the avalanche breakdown occurs because of the collision of free electrons with atoms. Both these breakdowns can occur simultaneously.