Compared with an ordinary p-n diode, a Schottky diode exhibits which combination of reverse saturation current and cut-in voltage?
Electronics and Communication Engineering
Electronic Devices and Circuits
Difficulty: Easy
Choose an option
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Ahas higher reverse saturation current
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Bhas higher reverse saturation current and higher cut in voltage
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Chas higher reverse saturation current and lower cut in voltage
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Dhas lower reverse saturation current and lower cut in voltage
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Ehas lower reverse saturation current and higher cut in voltage
Answer
Correct Answer: has higher reverse saturation current and lower cut in voltage
Explanation
Introduction / Context:Schottky diodes use a metal–semiconductor junction. Their transport and I-V characteristics differ from p-n junctions, offering low forward drop and fast switching at the expense of higher leakage.
Given Data / Assumptions:
- Device types: Schottky diode vs p-n diode.
- Properties compared: reverse saturation current (leakage) and forward cut-in voltage.
Concept / Approach:Due to the metal–semiconductor barrier and majority-carrier conduction, Schottky diodes typically have low forward voltage (about 0.2–0.4 V) and relatively high reverse leakage compared with silicon p-n diodes (about 0.6–0.7 V forward drop, lower leakage).
Step-by-Step Solution:
Step 1: Identify forward behavior: Schottky has lower cut-in voltage.Step 2: Identify reverse behavior: Schottky has higher leakage (reverse saturation current) at a given reverse voltage.Step 3: Select the option reflecting both facts.Verification / Alternative check:
Datasheets and application notes consistently show Schottky forward drop lower than silicon p-n and leakage higher, especially at elevated temperatures.Why Other Options Are Wrong:
A: Incomplete; misses forward-voltage aspect.B: Incorrect; forward drop is not higher.D/E: Misstate one or both trends.Common Pitfalls:
Confusing Schottky with germanium p-n diodes; conflating forward drop with conduction loss only and ignoring leakage impact on efficiency.Final Answer:
has higher reverse saturation current and lower cut in voltage