He aha ka MOSFET? He aha nā palena nui?

Ke hoʻolālā ʻana i kahi lako mana hoʻololi a i ʻole kaʻa kaʻa kaʻa kaʻa me ka hoʻohana ʻanaMOSFET, nā mea e like me ka on-resistance, ka nui o ka volta, a me ka nui o kēia manawa o ka MOS e noʻonoʻo ʻia.

ʻO nā paipu MOSFET he ʻano FET hiki ke hana ʻia ma ke ʻano he hoʻonui a hoʻopau paha, P-channel a i ʻole N-channel no ka huina o 4 ʻano. Hoʻohana pinepine ʻia nā NMOSFET hoʻonui a me nā PMOSFET hoʻonui, a ʻōlelo pinepine ʻia kēia mau mea ʻelua.

ʻO kēia mau mea ʻelua i hoʻohana pinepine ʻia ʻo NMOS. ʻO ke kumu he liʻiliʻi a maʻalahi ke kūʻē conductive. No laila, hoʻohana pinepine ʻia ʻo NMOS i ka hoʻololi ʻana i ka lako mana a me nā noi kaʻa kaʻa.

I loko o ka MOSFET, hoʻonoho ʻia kahi thyristor ma waena o ke kahawai a me ke kumu, he mea nui loa ia i ka hoʻokele ʻana i nā ukana inductive e like me nā kaʻa, a aia wale nō i loko o kahi MOSFET hoʻokahi, ʻaʻole maʻamau i loko o kahi puʻupuʻu kaapuni.

Aia ka capacitance Parasitic ma waena o nā pine ʻekolu o ka MOSFET, ʻaʻole pono mākou, akā ma muli o nā palena o ke kaʻina hana. ʻO ka hele ʻana o ka capacitance parasitic e ʻoi aku ka paʻakikī i ka hoʻolālā ʻana a i ʻole ke koho ʻana i kahi kaapuni kaʻa, akā ʻaʻole hiki ke pale ʻia.

 

ʻO nā palena nui oMOSFET

1, hāmama uila VT

Volta wehe (ʻike pū ʻia ʻo ka volta paepae): i koi ʻia ka volta puka e hoʻomaka i ka hana ʻana i kahi ala conductive ma waena o ke kumu S a me ka wai D; maʻamau N-channel MOSFET, VT ma kahi o 3 ~ 6V; ma o ka hoʻomaikaʻi kaʻina hana, hiki ke hoʻemi ʻia ka waiwai MOSFET VT i 2 ~ 3V.

 

2, DC hoʻokomo kūʻē RGS

ʻO ka lakio o ka voli i hoʻohui ʻia ma waena o ka pou kumu puka a me ka puka o kēia manawa Hōʻike ʻia kēia ʻano e ke kahe o ka puka e kahe ana ma ka ʻīpuka, hiki ke maʻalahi ka MOSFET's RGS ma mua o 1010Ω.

 

3. E hoʻokahe i ke kumu hoʻokahe BVDS voltage.

Ma lalo o ke kūlana o VGS = 0 (hoʻonui ʻia), i ke kaʻina o ka hoʻonui ʻana i ke kahe wai punawai, piʻi nui ka ID i ka wā i kapa ʻia ai ka VDS i ka punawai hoʻohaʻahaʻa punawai BVDS, piʻi nui ka ID ma muli o nā kumu ʻelua: (1) avalanche ka haki ʻana o ka papa hoʻopau kokoke i ke kahawai, (2) ka haki ʻana o ke komo ʻana ma waena o ka ʻauwai a me nā pou kumu, kekahi mau MOSFET, he ʻoi aku ka lōʻihi o ka auwaha pōkole, e hoʻonui i ka VDS i mea e hoʻonui ʻia ai ka papa hoʻoheheʻe i ka ʻāina kumu. e hana ana i ka lōʻihi o Channel he zero, ʻo ia hoʻi, e hana i kahi hoʻoheheʻe wai-kumu, ke komo ʻana, ʻo ka hapa nui o nā mea lawe i ka ʻāina kumu e huki pololei ʻia e ke kahua uila o ka papa depletion i ka ʻāpana wai, e hopena i kahi ID nui. .

 

4, BVGS kumu hoʻohaʻahaʻa uila

Ke hoʻonui ʻia ka volta puka, ʻo ka VGS i ka wā i hoʻonui ʻia ai ka IG mai ka ʻole, ua kapa ʻia ʻo ka puka puka breakdown voltage BVGS.

 

5、Haʻahaʻa alapine transconductance

Inā he waiwai paʻa ka VDS, ua kapa ʻia ka ratio o ka microvariation o ke kahawai wai i ka microvariation o ka volta kumu puka i hoʻololi ʻia i kapa ʻia he transconductance, e hōʻike ana i ka hiki ʻana o ka puliki puka puka e hoʻomalu i ke kahawai wai, a he ʻano nui e hōʻike ana i ka hiki ke hoʻonui i kaMOSFET.

 

6, on-kū'ē RON

Hōʻike ka RON i ka hopena o ka VDS ma ka ID, ʻo ia ka inverse o ka pali o ka laina tangent o nā hiʻohiʻona wai ma kekahi wahi, ma ka ʻāina saturation, ʻaʻole e loli ka ID me ka VDS, he nui loa ka RON. waiwai, maʻamau i loko o nā ʻumi kilo-Ohms a hiki i nā haneli kilo-Ohms, no ka mea, ma nā kaapuni kikohoʻe, hana pinepine nā MOSFET i ka mokuʻāina o ka conductive VDS = 0, no laila i kēia manawa, hiki ke hoʻohālikelike ʻia ka RON on-resistance e ka kumu o ka RON e pili ana, no ka MOSFET maʻamau, ka waiwai RON i loko o kekahi mau haneli ohms.

 

7, inter-polar capacitance

Aia ka capacitance interpolar ma waena o nā electrodes ʻekolu: CGS kumu capacitance puka, capacitance puka wai CGD a me capacitance punawai CDS-CGS a me CGD ma kahi o 1 ~ 3pF, CDS ma kahi o 0.1 ~ 1pF.

 

8、ʻAno walaʻau alapine haʻahaʻa

Hoʻokumu ʻia ka walaʻau ma muli o nā hewa i ka neʻe ʻana o nā mea lawe i ka pipeline. Ma muli o kona hele ʻana, hiki mai ka volta maʻamau a i ʻole nā ​​ʻano like ʻole o kēia manawa ma ka pukana inā ʻaʻohe hōʻailona i hāʻawi ʻia e ka amplifier. Hōʻike pinepine ʻia ka hana walaʻau ma nā huaʻōlelo o ka noise factor NF. ʻO ka ʻāpana he decibel (dB). ʻO ka liʻiliʻi o ka waiwai, ʻoi aku ka liʻiliʻi o ka walaʻau i hana ʻia e ka paipu. ʻO ka mea kani haʻahaʻa haʻahaʻa ka mea kani i ana ʻia i ka pae haʻahaʻa haʻahaʻa. ʻO ke kumu walaʻau o kahi paipu hopena kahua e pili ana i kahi dB liʻiliʻi, emi ma mua o ka triode bipolar.