Forward biased ideal diode=>no voltage drop?

[pyroknife]

Forward biased "ideal" diode=>no voltage drop?

Does a forward biased ideal diode have no voltage drop?

 

[vk6kro]

Yes, although it is difficult to say how zero volts can be called forward bias.

 

[ehild]

Of course, there is some voltage drop across a forward biased diode, but small. See the diode characteristics below.

When we speak abut an ideal diode, we either assume zero forward voltage or constant (0.7 V for Si diodes).

ehild

 

[vk6kro]

The "ideal diode" is a convenient fiction which is used when the actual voltage across the diode doesn't matter enough to be included in a calculation.

This is often the case in high voltage designs where the 0.7 volt drop across the diode is trivial compared with the much higher voltages in the circuit.

A voltage of zero volts can't have a polarity.

 

[vk6kro]

An ideal diode would have the vertical forward conducting line on the "Y" axis not to the right of it as these graphs show.

 

[cabraham]

Yes, although it is difficult to say how zero volts can be called forward bias.

Ideal diode has zero volts with non-zero forward current. "Forward biased" refers to direction of conduction current. An ideal diode conducts perfectly in 1 direction (no forward voltage drop). It blocks perfectly in reverse (no leakage current).

Ideal diode has zero volts with non-zero amps in forward direction, vice-versa in reverse.

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Claude