mosfet characteristics (ece126: laboratory 1)

7/21/2019 MOSFET Characteristics (ECE126: Laboratory 1)

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NIOS gna VIOS Clgrgct`rdstdcs

St`p 7:

Conn`ct tl` NIOS gna VIOS. Sdiuegt` tl` Das – Xbs clgrgct`rdstdcs curv`.

Ql`s` gr` tl` SVDC@ coa`s hor kotl NIOS

gna VIOS conn`ctdons. Gs dt ds oks`rvà,

NIOS gna VIOS lgs e`nbtl oh 7<u gna

3.8<u, r`sp`ctdvèy. Kotl lgs tl` sgi`

wdatl oh 6.0<u.

Hor IOSH@QS, k`hor` tl` cldp ds k`dnb

ngià, “i— iust k` put k`hor` lgna. Hor

dn tlds gctdvdty, cldps gr` ngià ―ijèora’.

Hor SVDC@ syntgx:

―ijèora va vb bna bna ncl e97<u

w96.0<u’, a`cegr`s ―ijèora’.

―Xa va bna 7.<’, gssdbns g voetgb` sourc`,

Xa97.<X, on tl` argdn oh ―ijèora’.

―.edk “5hde`pgtl>hde`ngi`— `ntryngi`’,

edkrgry cgee= hde`pgtl, pgtl to g hde`=

hde`ngi`, ngi` oh g hde` to dnceua` dn tl`

agtg hde`= `ntryngi`, `ntry ngi` hor tl`

s`ctdon oh tl` edkrgry hde` to dnceua`.

―QQ’, NIOS typdcge, VIOS typdcge= tl`

sp`à oh tl` trgnsdstor.

―.ac va 6 7.< 6.67’, p`rhoris AC gngeysds

oh va hroi 6X to 7.<X, sgipednb `v`ry6.67X.

―.prok` d7(ijèora)’, argwn Das oh

―ijèora’ hor peottdnb.

―.op’, cgecuegt`s tl` sigee sdbnge ioaè

pgrgi`t`rs oh g IOS hor g bdv`n

op`rgtdon podnt= dt wdee edst tl` hoeeowdnb

dnhorigtdon: da, vbs, vas, k`tg, bi gna

vtl.



Ql` brgpl slows tlgt gn NIOS lgs Xbs tlgt iust k` br`gt`r tlgt Xtl so tlgt tl` Da cgn

heow (tl` hegt edn` slows tlgt tl` Xbs ada not `xc`à tl` Xtl). Dt lgs g tlr`sloea voetgb` oh

gpproxdigtèy 137iX gs dt gpp`grs dn tl` ―.eds’ hde` oh tl` sdiuegtdon. Ql` tlr`sloea voetgb` ds

r`gclà wl`r` argdn curr`nt è`vgt`s. Hor Xbs, k`tw``n 6X gna 6.2X, Das ds n`grey z`ro dnadcgtdnb

tlgt `qudvge`nt r`sdstgnc` k`tw``n tl` argdn gna sourc` t`ridnges ds `xtrìèy ldbl. Onc` Xbs

r`gcl`s 6.2X, tl` curr`nt dncr`gs`s rgpdaey wdtl Xbs dnadcgtdnb tlgt tl` `qudvge`nt r`sdstgnc` gt

tl` argdn a`cr`gs`s wdtl dncr`gsdnb bgt`-sourc` voetgb`. Gs dt op`rgt`s, Das – Xbs curv` rds`s

qugargtdcgeey, dt occurs dn tl` sgturgtdon r`bdon. Qypdcgeey, Xas ds hdxà wl`n Das ds peottà gs

hunctdon oh Xbs.

Qlds ds tl` ―.eds’ hde` oh tl` NIOS tlroubl

tl` sdiuegtdon. Gs procurà, tl`

coipon`nt ds dn sgturgtdon wdtl Da wldcl

ds `quge to 8.8uG.

|Xtn|



Ql` brgpl slows tlgt g VIOS lgs Xbs tlgt iust k` e`ss tlgt Xtl so tlgt tl` Da cgn heow

(tl` hegt edn` slows tlgt tl` Xbs ada not `xc`à tl` Xtl). Dt lgs g tlr`sloea voetgb` oh

gpproxdigtèy -3<7iX gs dt gpp`grs dn tl` ―.eds’ hde` oh tl` sdiuegtdon. Ql` VIOS trgnsdstor

dnput clgrgct`rdstdc ds gngeobous to tl` NIOS trgnsdstor `xc`pt Das gna Xbs poegrdtd`s gr`

r`v`rsà. Xas ds n`bgtdv` gna gpproxdigtèy -6.7X. Gaadtdongeey, tl` bgt` ds gt g voetgb` eow`rtlgn tl` sourc` t`ridnge voetgb` to gttrgct loe`s to tl` clgnnè surhgc`.

Qlds ds tl` ―.eds’ hde` oh tl` VIOS tlroubl

tl` sdiuegtdon. Gs oktgdnà, tl`

coipon`nt ds dn sgturgtdon wdtl Da wldcl

ds gpproxdigtèy ̀ quge to -8.8uG.

|Xtp|



St`p ;:

Adsconn`ct tl` bgt` gna tl` argdn oh tl` IOS. Ql`n, gssdbn tl` adhh`r`nt vgeu`s oh Xbs to

dts bgt` t`ridnge. Sdiuegt` tl` Das – Xbs clgrgct`rdstdc curv`.



NIOS gna VIOS lgs e`nbtl oh 76.;4u gna

7.<8u, r`sp`ctdvèy. Kotl lgs tl` sgi`

wdatl oh 6.0<u.


ngià, “i— iust k` put k`hor` lgna. Hor dn

tlds gctdvdty, cldps gr` ngià ―ijèora’.

Hor SVDC@ syntgx:

―ijèora va vb bna bna ncl e976.;4u




―Xb Xb bna 7.1’, gssdbn g voetgb` sourc`,

Xb97.1, on tl` bgt` oh ―ijèora’.


edkrgry cgee= hde`pgtl, pgtl to g hde`= hde`ngi`,

ngi` oh g hde` to dnceua` dn tl` agtg hde`=

`ntryngi`, `ntry ngi` hor tl` s`ctdon oh

tl` edkrgry hde` to dnceua`.

―.optdon post prok`’, brgpl noage voetgb`s,

èì`nts curr`nts, cdrcudt r`spons`,

geb`krgdc `xpr`ssdons hroi tl` trgnsd`nt

gngeysds, AC sw``ps gna GC gngeysds= dt

`ngke`s oney sè`ctdv` prokdnb aon` dn

―.prok`’ stgtì`nts.



―.get`r’, ds usà to r`-run tl` sdiuegtdon

wdtl g ioadhdà n`tedst= l`r`, Xbs ds get`rà

wdtl clos`n vgeu`s.



Ql` brgpl gkov` adspegys tl` NIOS trgnsdstor output clgrgct`rdstdc peot Das – Xas wdtl

s`v`rge vgeu`s oh Xbs. Ql` edn`gr r`bdon, sgturgtdon r`bdon gna tl` kr`gm-aown gr` geso

adstdnbudslà wl`n tl` a`vdc` ds on. Dn tl` edn`gr r`bdon (wl`n Xbs 5 Xas + Xtn), gs tl` argdn

curr`nt dncr`gs`s, Xas dncr`gs`s. Soi`low, tl` IOSH@Q gcts sort oh edm` g r`sdstor. Dn tl`

sgturgtdon r`bdon (Rl`n Xbs > Xas + Xtn), tl` Das edn`s gr` hegt k`cgus` tl` curr`nt ao`s notdncr`gs` gs gny ior` Xas dncr`gs`s. Qo oktgdn tl` sgturgtdon, ds to suppey `noubl voetgb` untde

`v`ntugeey tl` rds` dn tl` curr`nt wdee igm` no adhh`r`nc` to tl` curr`nt. Kr`gm-aown i`gns tl`

dnput voetgb` e`vè ds ldbl`r tlgn tl` ldbl`st geeowgke` pow`r suppey e`vè. Rl`n tl` trgnsdstor

ds ohh (Xbs 5 Xtn), Das ds z`ro hor gny Xas vgeu`.

Qlds ds tl` ―.eds’ hde` oh tl` NIOS

trgnsdstor tlroubl tl` sdiuegtdon. Gs g

r`suet, tl` coipon`nt ds dn sgturgtdon

wdtl Da tlgt ds gpproxdigtèy `quge to

8.8uG.

Xbs97.1X

Xbs97.;X

Xbs96.<X

Kr`gm Aown

Xbs96X

Sgturgtdon [`bdon

Edn`gr [`bdon



Ql` brgpl gkov` slows tl` VIOS trgnsdstor output clgrgct`rdstdc peot Das – Xas wdtl

s`v`rge vgeu`s oh Xbs. Ql` edn`gr r`bdon, sgturgtdon r`bdon gna tl` kr`gm-aown gr` geso

adstdnbudslà wl`n tl` a`vdc` ds on. Ql` argdn curr`nt dn sgturgtdon ds vdrtugeey dna`p`na`nt oh

Xas gna tl` trgnsdstor gcs gs curr`nt sourc`. Qlds ds k`cgus` tl`r` ds no cgrrd`r dnv`rsdon gt tl`

argdn r`bdon oh tl` clgnnè. Cgrrd`rs gr` pueeà dnto tl` ldbl è`ctrdc hdèa oh tlàrgdn/sukstgnc` pn junctdon gna `j`ctà out oh tl` argdn t`ridnge. G n`gr constgnt curr`nt ds

ardv`n hroi trgnsdstor no igtt`r tl` argdn-to-sourc` voetgb`. Ql` VIOS trgnsdstor Das v`rsus Xas

curv`s lgs sdidegr slgp` to tlgt dn NIOS, kut tl` voetgb` gna curr`nt poegrdtd`s gr` n`bgtdv` to

gccount hor loe` dnv`rsdon gna argdn curr`nt tlgt `nt`rs tl` trgnsdstor.

Qlds ds tl` ―.eds’ hde` oh tl` VIOS trgnsdstortlroubl tl` sdiuegtdon. Gs procurà, tl`

coipon`nt ds dn sgturgtdon wdtl Da tlgt ds

`quge to -8.8uG.

Kr`gm Aown

Sgturgtdon [`bdon

Edn`gr [`bdon

Xbs9-7.1X

Xbs9-6.<X

Xbs9-6.<X

Xbs96X



St`p 3:

Hoeeow St`p ;, clgnb` tl` clgnnè e`nbtl. Sdiuegt` tl` Das-Xbs clgrgct`rdstdc curv`.





wdatl oh 6.0<u.


ngià, “i— iust k` put k`hor` lgna. Hor dn

tlds gctdvdty, cldps gr` ngià ―ijèora’.

Hor SVDC@ syntgx:

―ijèora va vb bna bna ncl e976.;4u




―Xb Xb bna 7.1’, gssdbn g voetgb` sourc`,

Xb97.1, on tl` bgt` oh ―ijèora’.


edkrgry cgee= hde`pgtl, pgtl to g hde`= hde`ngi`,

ngi` oh g hde` to dnceua` dn tl` agtg hde`=

`ntryngi`, `ntry ngi` hor tl` s`ctdon oh

tl` edkrgry hde` to dnceua`.





geb`krgdc `xpr`ssdons hroi tl` trgnsd`ntgngeysds, AC sw``ps gna GC gngeysds= dt



―.ac va 6 0 6.67’, p`rhoris AC gngeysds oh

va hroi 6X to 0X, sgipednb `v`ry 6.67X.

―.prok` d7(ijèora)’, argwn Das oh ―ijèora’

hor peottdnb.



wdtl clos`n vgeu`s.



Ql` brgpl gkov` slows tl` NIOS trgnsdstor output clgrgct`rdstdc peot Das – Xbs. Ql`

clgnnè ds s`t to wdatl96.0<u, Xbs97.1, gna clgnb` dn tl` clgnnè e`nbtl. Gs oks`rvà, tl`

clgnnè e`nbtl ioauegtdon ghh`cts tl` curr`nt oh tl` NIOS dn tl` sgturgtdon r`bdon wlde` dts

clgnnè e`nbtl ds clgnbà. Ql` giount oh tl` dncrì`nt cgn k` r̀ aucà ky dncr`gsdnb tl`

clgnnè e`nbtl. Dt i`gns tlgt, dh IOSH@Q wdee k` usà gs g constgnt sourc`, g egrb`r clgnnèe`nbtl cgn proauc` g curr`nt wldcl ds ior` constgnt gna e`ss s`nsdtdv` to proc`ss vgrdgtdons.

Qlds ds tl` ―.eds’ hde` oh tl` NIOS trgnsdstor

tlroubl tl` sdiuegtdon. Gs gcqudrà, tl`

coipon`nt ds dn sgturgtdon wdtl Da tlgt ds

`quge to 8.8uG.

E92°

E94°

E91°

E976.;4°



Ql` brgpl gkov` adspegys tl` VIOS trgnsdstor output clgrgct`rdstdc peot D as – Xbs. Ql`

clgnnè ds s`t to wdatl96.0<u, Xbs9-7.1, gna clgnb` dn tl` clgnnè e`nbtl. Gs p`rc`dvà, tl`

clgnnè e`nbtl ioauegtdon ghh`cts tl` curr`nt oh tl` NIOS dn tl` sgturgtdon r`bdon wlde` dts

clgnnè e`nbtl ds clgnbà. Clgnnè e`nbtl ioauegtdon (or CEI), ds on` oh tl` s`v`rge slort-

clgnnè `hh`cts dn IOSH@Q scgednb. Dt ds g slort`ndnb oh tl` e`nbtl oh tl` dnv`rtà clgnnè r`bdon

wdtl dncr`gs` dn argdn kdgs hor egrb` argdn kdgs`s. Ql` r`suet oh CEI ds gn dncr`gs` dn curr`nt wdtl

argdn kdgs gna g ràuctdon output r`sdstgnc`. Ql` `hh`ct ds pronouncà tl` slort`r tl` sourc`-

to-argdn s`pgrgtdon, tl` a``p`r tl` argdn junctdon, gna tl` tldcm`r tl` oxda` dnsuegtor.

Qlds ds tl` ―.eds’ hde` oh tl` VIOS trgnsdstor

tlroubl tl` sdiuegtdon. Gs oktgdnà, tl`coipon`nt ds dn sgturgtdon wdtl Da tlgt ds

gpproxdigtèy ̀ quge to -8.8uG.

E92°

E91°

E94°

E97.24°



St`p 1:

S`t |Xbs| to g vgeu` sigee`r tlgn |Xt| to op`rgt` tl` IOS dn suktlr`sloea r`bdon.

Sdiuegt` tl` Das-Xbs clgrgct`rdstdc curv`.





wdatl oh 6.0<u.


ngià, “i— iust k` put k`hor` lgna. Hor

dn tlds gctdvdty, cldps gr` ngià ―ijèora’.

Hor SVDC@ syntgx:


edkrgry cgee= hde`pgtl, pgtl to g hde`=

hde`ngi`, ngi` oh g hde` to dnceua` dn tl`

agtg hde`= `ntryngi`, `ntry ngi` hor tl`

s`ctdon oh tl` edkrgry hde` to dnceua`.





geb`krgdc `xpr`ssdons hroi tl` trgnsd`nt

gngeysds, AC sw``ps gna GC gngeysds= dt



―.ac va 6 0 6.67’, p`rhoris AC gngeysds oh

va hroi 6X to 0X, sgipednb `v`ry 6.67X.

―.prok` d7(ijèora)’, argwn Das oh

―ijèora’ hor peottdnb.



wdtl clos`n vgeu`s.



Ql` brgpl deeustrgt`s tl` Das‑Xbs clgrgct`rdstdc curv`s oh gn NIOS trgnsdstor. Dn tl`

brgauge clgnnè gpproxdigtdon ioaèdnb oh IOSH@Q t`ridnge clgrgct`rdstdcs, gs dt stgtà

`gred`r, tlgt tl` argdn curr`nt ds da`ntdcgeey z`ro wl`n tl` bgt` voetgb` ds e`ss tlgn tl` tlr`sloea

voetgb`. Ql` popuegtdon oh iokde` è`ctrons una`r tl` bgt` provda`s g i`clgndsi hor clgrb`

heow k`tw``n tl` argdn gna sourc` `v`n |Xbs| 5 |Xt|, gna tlus tl`r` ds dn hgct g sigee, non-z`roargdn curr`nt tlroubl g IOSH@Q kdgsà kèow tlr`sloea. Qlds ds sdbndhdcgnt k`cgus` on gn

dnt`brgtà cldp wdtl ideedons oh trgnsdstors wldcl gr` supposà to k` ohh gna tl`r`hor` not

adssdpgtdnb gny pow`r, g edtte` curr`nt heowdnb tlroubl `gcl trgnsdstor cgn `gsdey gaa up to k` g

sdbndhdcgnt pow`r argdn, gna k` g sourc` oh l`gtdnb. Hurtl`rior`, IOSH@Q ds op`rgtà dn

suktlr`sloea r`bdon.

Qlds ds tl` ―.eds’ hde` oh tl` NIOS trgnsdstor

tlroubl tl` sdiuegtdon. Gs g r`suet, tl`

coipon`nt ds cut-ohh wdtl Da wldcl ds

gpproxdigtèy ̀ quge to 7.08nG.

Xas97.<X Xas97.3X

Xas96.<X



Ql` brgpl deeustrgt`s tl` Das‑Xbs clgrgct`rdstdc curv`s oh gn NIOS trgnsdstor. Dt ds not

totgeey corr`ct tlgt wl`n Xbs vgeu` oh g IOSH@Q ds sigee`r tlgn X t, dt wdee turn ohh gna Das wdee k`

`quge to z`ro, gs stgtà `gred`r. Dn hgct, wl`n Xbs ds sedbltey sigee`r tlgn Xt, tl`r` ds stdee g sigee

curr`nt heowdnb hroi tl` argdn to sourc`, tlus tl` IOSH@Q ds op`rgtà dn tl` suktlr`sloea

r`bdon. On` tldnb tlgt gee oh tl`s` cdrcudts lgv` dn coiion ds tlgt tl`y op`rgt` dn tl`suktlr`sloea r`bdon oh tl` IOSH@Q. Qlgt ds, tl`y us` tl` IOSH@Q—s clgrgct`rdstdcs wdtl tl`

bgt` kdgsà kèow tl` trgnsdstor's tlr`sloea voetgb`. Qlds ds rgr` hor IOSH@Q cdrcudts, dn wldcl

tl` hgct tlgt tl`y lgv` g slgrp trgnsdtdon hroi cutohh to conauctdnb ds tl` iost us`hue oh tl`

trgnsdstor's prop`rtd`s. Low`v`r, suktlr̀ sloea op`rgtdon geso lgs dts k`n`hdts. Dn tlds r`bdon, tl`

curr`nts tlroubl tl` trgnsdstor gr` `xtrìèy eow, ora`rs oh igbndtua` eow`r tlgn dn norige

op`rgtdon. Suktlr`sloea cdrcudts consui` `xtrìèy sigee giounts oh pow`r, wldcl ds

diportgnt wl`n you gr` trydnb to crgi igny tlousgnas oh tl`s` cdrcudts onto g sdnbe`

dnt`brgtà cdrcudt.

Qlds ds tl` ―.eds’ hde` oh tl` VIOS trgnsdstor

tlroubl tl` sdiuegtdon. Gs procurà, tl`

coipon`nt ds cut-ohh wdtl Da wldcl ds

gpproxdigtèy ̀ quge to -7.71nG.

Xas97.<XXas97.3X

Xas96.<X



WP@SQDONS:

7. Dh w` dncr`gs` R/E oh tl` a`vdc` dn St`p 7, wlgt clgnb`s wdee occur to tl` curv`?

Dncr`gsdnb tl` R/E oh tl` NIOS gna VIOS wdee r`suet to gn dncr`gs` dn tl` curv`—s seop`wdtl r`sp`ct to tl` y-gxds. Qlds ds au` to g a`cr`gs` dn tlr`sloea voetgb`. Ql`r` ds g n`à to

ràuc` tl` tlr`sloea voetgb` dn ora`r to igdntgdn p`rhorignc`. Rl`n dt ds k`dnb ràucà, tl`

trgnsdstor cgnnot k` swdtclà hroi coipe`t` turn-ohh to coipe`t` turn-on wdtl tl` edidtà

swdnb gvgdegke`.

;. Rl`n tl` adi`nsdons Rn/En `quge Rp/Ep, ao`s |Dasp|/Dasn `quge °p/°n?

Soeutdon:

(Rn/En 9 Rp/Ep)

usdnb,

DA 97

; λ (Xbs – Xtn); wl`n λ 9° cox

.

DN 97

; λn (Xbs – Xtn);

9

°p

°n

DN

DV 97

; λp (Xbs – Xtn);

9 °p

°n

DN

`qugtdnb tl` ; `qugtdons,

9

°p

°n

3. Rlgt règtdonsldp k`tw``n tl` clgnnè e`nbtl gna tl` seop` oh D as – Xas Clgrgct`rdstdc

Curv` oh NIOS gna VIOS?

Ql` curr`nt dncr`gsà gs tl` E ds a`cr`gsà (λp 9°p cox

, DA 9

λ (Xbs – Xtn); ).

1. Rl`n tl` IOSH@Q op`rgt`s dn suk-tlr`sloea r`bdon, wlgt ds tl` règtdonsldp k`tw``n

Xbs gna tl` seop` oh tl` Das – Xbs Clgrgct`rdstdc Curv`? Rlgt a`vdc`, `dtl`r VIOS or NIOS, lgs

tl` egrb`r seop`? Rly?

Ql` suk-tlr`sloea r`bdon ds a`t`ridnà ky tl` voetgb` dn tl` bgt`-sourc` voetgb` gna

tlus proportdonge to tl` curr`nt (tloubl idndige), gna sdnc` NIOS lgs g egrb`r curr`nt tlgn

VIOS, tlgt ds wly tl` NIOS lgs g egrb`r seop` dn tl` D as-X bs curv`.

mosfet characteristics (ece126: laboratory 1)

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