Diki Package MOSFETs

Kana iyo MOSFET yakabatana nebhazi uye pasi pekutakura, yakakwira voltage side switch inoshandiswa. Kazhinji P-channelMOSFETsanoshandiswa mune iyi topology, zvakare kune voltage drive kufunga. Kusarudza chiyero chemazuva ano Danho rechipiri nderokusarudza chiyero chezvino cheMOSFET. Zvichienderana nemaitiro edunhu, iyi chiyero chemazuva ano chinofanirwa kunge chiri chepamusoro ikozvino iyo mutoro unogona kumira pasi pemamiriro ese.

Zvakafanana nenyaya yemagetsi, mugadziri anofanira kuve nechokwadi kuti yakasarudzwaMOSFETinogona kumira chiyero chazvino, kunyangwe iyo system iri kugadzira spike currents. Iwo maviri azvino makesi akatariswa ndeye inoenderera modhi uye pulse spikes. Iyi parameter inoratidzwa neFDN304P DATASHEET, apo MOSFET iri munzvimbo yakagadzikana mukuenderera mberi kwekuita maitiro, apo ikozvino inoramba ichiyerera nemumudziyo.

Pulse spikes ndeye kana paine kuvhiya kukuru (kana spike) yezvino inoyerera nemumudziyo. Kana iyo yakanyanya ikozvino pasi pemamiriro ezvinhu aya yakatemwa, ingori nyaya yekusarudza zvakananga mudziyo unokwanisa kumirisana nehukuru huno.

Mushure mekusarudza ikozvino yakarongwa, kurasikirwa kwekufambisa kunofanirawo kuverengwa. Mukuita, maMOSFET haasi maturusi akakodzera nekuti pane kurasikirwa kwesimba panguva yekuitisa conduction, iyo inonzi conduction kurasikirwa.

Iyo MOSFET inoita senge inochinjika resistor kana iri "pa", sekutemerwa neRDS (ON) yechishandiso, uye inosiyana zvakanyanya nekushisa. Kuraswa kwesimba kwechishandiso kunogona kuverengerwa kubva kuIload2 x RDS (ON), uye sezvo iyo-inopikisa ichisiyana nekupisa, kupera kwemagetsi kunosiyana zvichienderana. Iyo yakakwirira iyo VGS yakashandiswa kune MOSFET, iyo idiki iyo RDS (ON) ichave; ukuwo iyo yakakwirira iyo RDS(ON) ichave. Kune sisitimu dhizaini, apa ndipo panopinda tradeoffs zvichienderana neiyo system voltage. Kune madhizaini anotakurika, zviri nyore (uye zvakajairika) kushandisa yakaderera voltages, nepo kune maindasitiri madhizaini, yakakwirira voltages inogona kushandiswa.

Ziva kuti iyo RDS(ON) kuramba inokwira zvishoma neyazvino. Misiyano pamhando dzakasiyana dzemagetsi eiyo RDS (ON) resistor inogona kuwanikwa mune tekinoroji data sheet rakapihwa nemugadziri.

Kuona Zvinodikanwa zveThermal Danho rinotevera pakusarudza MOSFET nderekuverenga zvinodikanwa zvekupisa zvehurongwa. Mugadziri anofanira kufunga nezvezviitiko zviviri zvakasiyana, iyo yakaipisisa kesi uye yechokwadi kesi. Zvinokurudzirwa kuti kuverenga kwechiitiko chakaipisisa chinoshandiswa, sezvo ichi chigumisiro chinopa muganhu mukuru wekuchengeteka uye inovimbisa kuti hurongwa hahuzokundiki.

Kune zvakare zvimwe zviyero zvekuziva paneMOSFETdatasheet; senge tembiricha yekupisa pakati pe semiconductor junction yeyakaputirwa mudziyo uye ambient nharaunda, uye yakanyanya tembiricha yekusangana. Tembiricha yekusangana kwechishandiso yakaenzana neyakakura ambient tembiricha pamwe neyakagadzirwa kupisa kwekupisa uye kupera simba (junction tembiricha = yakanyanya ambient tembiricha + [thermal resistance x power dissipation]). Kubva pane iyi equation iyo yakanyanya simba dissipation yehurongwa inogona kugadziriswa, inova netsanangudzo yakaenzana neI2 x RDS (ON).

Sezvo mugadziri akateya iyo yakanyanya ikozvino ichapfuura nepamudziyo, RDS (ON) inogona kuverengerwa tembiricha dzakasiyana. Zvakakosha kuziva kuti pakubata nemhando dzakareruka dzekupisa, mugadziri anofanirawo kufunga nezvekupisa kwesimba re semiconductor junction / device enclosure uye yakavharidzirwa / nharaunda; kureva, zvinodikanwa kuti bhodhi redunhu rakadhindwa uye pasuru hazvidziye nekukurumidza.

Kazhinji, PMOSFET, pachange paine parasitic diode iripo, basa re diode ndere kudzivirira sosi-drain reverse connection, yePMOS, mukana wepamusoro weNMOS ndewekuti vhezheni yayo inogona kuve 0, uye musiyano wevoltage pakati pe DS voltage haina kuwanda, nepo NMOS iri pamamiriro ezvinhu inoda kuti VGS ive yakakura kupfuura chikumbaridzo, izvo zvinozotungamira kune yekudzora voltage isingadzivisike yakakura kupfuura inodiwa voltage, uye pachava ne dambudziko risingakoshi. PMOS inosarudzwa senge switch yekudzora, kune maviri anotevera maapplication: yekutanga application, iyo PMOS yekuita sarudzo yemagetsi, kana V8V iripo, ipapo magetsi anopihwa neV8V, iyo PMOS ichadzimwa, iyo VBAT. haina kupa voltage kuVSIN, uye kana V8V yakaderera, VSIN inoshandiswa ne8V. Ziva kugadzwa kweR120, chinopikisa chinodhonza zvishoma nezvishoma gedhi regedhi pasi kuti ive nechokwadi chekubatidzwa kwePMOS, njodzi yenyika inobatana negedhi repamusoro impedance yakambotsanangurwa kare.

Mabasa eD9 neD10 ndeekudzivirira voltage back-up, uye D9 inogona kusiiwa. Zvinofanira kucherechedzwa kuti DS yedunhu inonyatso kushandurwa, kuitira kuti basa rekushandura chubhu haigone kuwanikwa nekufambiswa kweiyo diode yakanamirwa, iyo inofanirwa kucherechedzwa mune inoshanda maapplication. Mudunhu iri, chiratidzo chekutonga chePGC chinodzora kana V4.2 ichipa simba kuP_GPRS. Iyi dunhu, iyo sosi uye materminal terminals haana kubatana kune zvakapesana, R110 uye R113 iripo mupfungwa yekuti R110 yekudzora gedhi ikozvino haina kunyanyokura, R113 control gedhi zvakajairika, R113 kukwevera kumusoro, sePMOS, asiwo. inogona kuoneka sekudhonza-kumusoro pachiratidzo chekudzora, kana MCU yemukati mapini uye kudhonza-kumusoro, ndiko kuti, kubuda kweiyo yakavhurika-drain kana iyo inobuda isingadzingi PMOS, pa panguva ino, iyo Inoda yekunze voltage kuti ipe iyo yekudhonza-kumusoro, saka resistor R113 inotamba mabasa maviri. r110 inogona kuva idiki, kusvika ku100 ohms inogona kuva.