On the forum, post #12, Ghar claimed that the proof gain-bandwidth product from wikipedia is awful and he gave another proof but with feedback.

1. https://en.wikipedia.org/wiki/Gain%E2%80%93bandwidth_product
2. http://forum.allaboutcircuits.com/threads/op-amps-and-gain-bandwidth-product.43799/

The wikipedia proves gain-bandwidth product constant for open-loop opamp while Ghar proved for closed loop opamp.

Could you please tell me that if the wikipedia proof is wrong? I don't see any thing wrong with it. However, reading Ghar's post makes me confused.

I attach the Ghar's post in the image below just in case some member can't access it.

Note: Let's consider single pole opamp only.

On the forum, post #12, Ghar claimed that the proof gain-bandwidth product from wikipedia is awful and he gave another proof but with feedback.

1. https://en.wikipedia.org/wiki/Gain%E2%80%93bandwidth_product
2. http://forum.allaboutcircuits.com/threads/op-amps-and-gain-bandwidth-product.43799/

The wikipedia proves gain-bandwidth product constant for open-loop opamp while Ghar proved for closed loop opamp.

Could you please tell me that if the wikipedia proof is wrong? I don't see any thing wrong with it. However, reading Ghar's post makes me confused.

I attach the Ghar's post in the image below just in case some member can't access it.

Note: Let's consider single pole opamp only. This site also gave the same proof as wikipedia.

http://masteringelectronicsdesign.com/why-is-the-op-amp-gain-bandwidth-product-constant/

On the forum, post #12, Ghar claimed that the proof gain-bandwidth product from wikipedia is awful and he gave another proof but with feedback.

1. https://en.wikipedia.org/wiki/Gain%E2%80%93bandwidth_product
2. http://forum.allaboutcircuits.com/threads/op-amps-and-gain-bandwidth-product.43799/

The wikipedia proves gain-bandwidth product constant for open-loop opamp while Ghar proved for closed loop opamp.

Could you please tell me that if the wikipedia proof is wrong? I don't see any thing wrong with it. However, reading Ghar's post makes me confused.

I attach the Ghar's post in the image below just in case some member can't access it.

Note: Let's consider single pole opamp only.

On the forum, post #12, Ghar claimed that the proof gain-bandwidth product from wikipedia is awful and he gave another proof but with feedback.

1. https://en.wikipedia.org/wiki/Gain%E2%80%93bandwidth_product
2. http://forum.allaboutcircuits.com/threads/op-amps-and-gain-bandwidth-product.43799/

The wikipedia proves gain-bandwidth product constant for open-loop opamp while Ghar proved for closed loop opamp.

Could you please tell me that if the wikipedia proof is wrong? I don't see any thing wrong with it. However, reading Ghar's post makes me confused.

I attach the Ghar's post in the image below just in case some member can't access it.

Note: Let's consider single pole opamp only.