Question

Sketch structure of depletion-enhancement MOS Filed Effect Transistor (DE-MOSFET). Explain essence of principle of operation of E-MOSFET connected in common-source configuration. Sketch and explain shapes of corresponding common-source transfer curves and common-source output curves (drain IV characteristics). Explain why input IV characteristics are not used in the case of FET.

Answer 1

sio, layev Draim Psubstcle DS Cati Metal contact sourceラ Struchure t depletion enhancement Mos FET The construction et enhance ment MOsFET ie E.MosfET b SImu difterence io the absene ot N channel in the case E MOSFET simela to the constructhon ot P-type MOSFET But onL OPERATION E-MOSFET operates in only One mode te n Enhance ment- าว่า PoN. channl EMosFET, V as alday positive Case I 3m this case ID:0 le draincumentw zero, due to t1c

absenc ot N channel which dosnot permil the floro cf ree charge camier Case LT To Operate an E-MOSFET , we foue to Induce.a η.chan the device when Vos - tVe , the minoity charre cawic P substrate will be attracded towawds the gata tesm lh minal and majority charge the Stoz layea holes ana mepiled auny tron. the maanitude Vas increases the Concertatum of electors deposcted near the SiO2 vegion incstaje for a ces Yus , there will be an unduted ท.channel which supports the tto" stain vaua. cument trom dyain to Soteminal and that vals o Vas co Known as These voa o V deposted near tre sto, Lajen aluo incse the value Ip Sio, laiyer also increase which n tuns increaxs keeping Vas constont, if Vs incres tren the vottage at terminal tncrases attracbng more number ef elecon rom the induced n-channel touoards it stablishnj mere. dłrain cumnt in thu opposite decton

Lue to increas in Vo, the voltage diffesence be tween dnin and gate terminal decreases γeJulbng 2n TCduchm of attracting oestowards the electron Thus the cha mear tre crain ter minal nnel idi decrease \ Eventually ,사 VDS 1ncm ases, the pinch ett (onditen arrise" in Saturaton Condetion The selaboniship hetuien Voc saknahm and Vas ia jeien h,y Ds) satturakiaVjs - VT Thres hold vottare lov Trans-teゴ Characteushscurve curve. Both he Curve funchons o wokin oprahon an alady mentioned i above

explanation of why Input IV characderutio are not used in caie FET For amy characteristis whuh to e draion ue need ie voitage and curxent Τη we fave an draub Input charackersties FET, στα en. Tnput voltage e Vos ,but ie donlt have the input cument- we don't have the 'input cuTrent. As Because icose or al tWhat Input vol FET, the input cunent o very small most Zoro because ot Revesse biased ate S0 no mattes we have but the Input current io alaaiy oero Inpl so, it not possible to dT0u0 Λ 1 o( V characfersties FET.