Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

How to calculate ro of a MOS?

Status
Not open for further replies.

urian

Full Member level 3
Joined
Sep 3, 2009
Messages
154
Helped
10
Reputation
20
Reaction score
3
Trophy points
1,298
Activity points
2,500
hi,there
I'm using IC5141 to design circuit.I want to know the ro of a MOS,but I only find ron in the DC operating point form.So where can I find the ro,or I have to calculate it through some parameters?

Regards
 

Re: how to calculate ro?

You are provided with gds after the simulator calculates the DC operating point of your circuit.So take this value and using the formula ro=1/gds you have the small signal output resistance of your MOS transistor.
 
Re: how to calculate ro?

thx,jimito13,but why it provide gds instead of ro?
 

Re: how to calculate ro?

You should ask Cadence. However, it will not be a technical problem.
 

because usually the simulators calculate transconductances and capacitances.
 

so,what does the Ron be used for?
 

When you operate the transistor in deep triode region (Vds<<2Veff) the drain current is approximately a linear function of Vds.The linear relationship implies that the path from source to drain can be represented by a linear resistor.This is the Ron.
 
  • Like
Reactions: urian

    urian

    Points: 2
    Helpful Answer Positive Rating
hi,jimito13
when the mos is working in saturation region ,I find there is also Ron in the DC operating point print,then,what does the Ron mean under this circumstance?Does it also mean the resistor from drain to source?
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top