I am studying analog circuits, and this question below has been troubling me for a long time. Can someone help me take a look at it?

 

Hi F,
Welcome to AAC,
Is this a Homework or College assignment question.?
E

 

Hi F,
Welcome to AAC,
Is this a Homework or College assignment question.?
E

It's an interview question that was done on-site, and even after reviewing it, I still couldn't solve it.

 

I don't know much about this kind of amplifier but your post does not contain anywhere near the amount of information needed to answer those questions. For example, what are those MOSFETS?

 

I don't know much about this kind of amplifier but your post does not contain anywhere near the amount of information needed to answer those questions. For example, what are those MOSFETS?

These would be MOSFETS fabricated on a single chip with a feature size defined by the fabrication process. That feature size is not specified and neither are the parameters of the process. The question supposes that you can rattle off the relevant equations and express the answer in terms of Vth, Vgs, and I. There is no subscript in the I, but I presume it would be the drain current of one of the transistors.

 

I is specified as being the current passing through M14.

For the second part of the question, focus on the M13, R2, M14, M15 chain. What do you know about the current in each of these devices? What is required to keep all of the transistors in saturation?

You might need to make some assumptions (and, if you do, be sure to state them) about the MOSFET parameters, such as whether Vt is the same for both NFET and PFET transistors or whether all of the transistors of the same type are the same size.