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Mhan
Mhan
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Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow)
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description here

enter image description here

Source Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

enter image description here

enter image description here

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow)
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow)
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description here

enter image description here Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

enter image description here

enter image description here

deleted 126 characters in body
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Mhan
Mhan
  • 730
  • 1
  • 11

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow)
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description hereenter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow)
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow)
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

deleted 126 characters in body
Source Link
Mhan
Mhan
  • 730
  • 1
  • 11

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

What I want to do, for example, isTo make ΔID/ΔVGS and get the amountresult of change from 0V to 0.5V, 0transconductance ı write dot parameters as follow:

.5Vparam Vhigh - 0V = 0{X}
.5V or 1Vparam Vlow {X- 00.5 up to 12 V}
. I want to do the same forsave V(Vg) Id corresponding to the amount of change and find their ratio.

Should I continue for every value like below:(M1)
.meas TRAN VgId_high FIND VId(outM1) WHEN V(XVg)=0.5=Vhigh
.meas TRAN VgId_low FIND VId(outM1) WHEN V(XVg)=1=Vlow
.meas TRAN Vg FIND Vgm PARAM (outId_high-Id_low) WHEN V/(XVhigh-Vlow)=1.5 . . 
.print gm

doingWhen ı check the same for Id and usingSpice error log .meas DELTA param makes the process too long, Id_high - Id_low and gm values are negative.

Maybe I am wrong but Why ? What is there any other correct way to do itwrong with my dot parameters ?

enter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

What I want to do, for example, is the amount of change from 0V to 0.5V, 0.5V - 0V = 0.5V or 1V - 0.5 up to 12 V. I want to do the same for Id corresponding to the amount of change and find their ratio.

Should I continue for every value like below:
.meas TRAN Vg FIND V(out) WHEN V(X)=0.5
.meas TRAN Vg FIND V(out) WHEN V(X)=1
.meas TRAN Vg FIND V(out) WHEN V(X)=1.5 . . .

doing the same for Id and using .meas DELTA param makes the process too long.

Maybe I am wrong but is there any other correct way to do it?

enter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

Below is a very simple circuit to extract the transconductance value of the MOSFET.

As it is known, transconductance is known as Delta (Id) / Delta (Vgate).

For the gate voltage, I defined it as .step param X 0 12 0.5.

To make ΔID/ΔVGS and get the result of transconductance ı write dot parameters as follow:

.param Vhigh {X}
.param Vlow {X-0.5}
.save V(Vg) Id(M1)
.meas TRAN Id_high FIND Id(M1) WHEN V(Vg)=Vhigh
.meas TRAN Id_low FIND Id(M1) WHEN V(Vg)=Vlow
.meas TRAN gm PARAM (Id_high-Id_low)/(Vhigh-Vlow) 
.print gm

When ı check the Spice error log , Id_high - Id_low and gm values are negative. Why ? What is wrong with my dot parameters ?

enter image description here

enter image description here

Source: https://www.mouser.com.tr/datasheet/2/240/media-3322045.pdf

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Mhan
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