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.

finding VGS value for diode connected MOSFET

Status
Not open for further replies.

kiransbaddi

Member level 2
Member level 2
Joined
Nov 30, 2015
Messages
51
Helped
0
Reputation
0
Reaction score
0
Trophy points
6
Activity points
427
please help me find the value of VGS

diode.PNG
 

Hi,

I = ( V1 - V_gs) / 10k (calculated with the voltage across R which depends on V_gs)
And the mosfet has it's own characteristic.
I mainly depends on V_gs, but also on V_ds.

Now you have two I, both needs to be equal.
You can solve this mathematically or by drawing a chart.

Klaus
 

    V

    Points: 2
    Helpful Answer Positive Rating
You have the MOSFET inverted, so the MOSFET will conduct through the substrate diode.
Since you have the gate tied to the source the Vgs is zero.

For a diode-connected MOSFET you would invert the MOSFET with the gate still connected to V1.
In that case Vgs would be slightly above its threshold voltage.
 
As mentioned by crutschow, the substrate connection has to be corrected.

For a first order estimation, solve the idealized quadratic MOSFET equation.
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top