Yuav xaiv TVS diodes li cas

Thaum xaiv TVS, cov hauv qab no tseem ceeb yuav tsum tau xav txog:

(1) Yog tias TVS zoo li tuaj yeem tiv taus qhov hluav taws xob (surge voltages) los ntawm ob qho kev qhia, nws yuav tsum yog bipolar, txwv tsis pub nws tuaj yeem yog unipolar.

(2) Tus nqi Vc ntawm TVS xaiv yuav tsum qis dua qhov siab tshaj qhov hluav taws xob ntawm cov khoom tiv thaiv. "Vc yog qhov hluav taws xob ntawm lub diode nyob rau hauv lub xeev txiav, uas yog, qhov voltage uas dhau los ntawm TVS thaum lub sij hawm ESD surge xeev. ntawm kev puas tsuaj."

(3) TVS yuav tsum tsis txhob nyob rau hauv lub xeev tawg nyob rau hauv ib txwm ua hauj lwm tej yam kev mob, zoo dua hauv qab VR. Qhov tsim nyog TVS yuav tsum raug xaiv raws li kev txiav txim siab ntawm ob qho tib si VR thiab VC cov cai.

Stabilizing raj

(4) Yog tias muaj qhov tseeb surge tam sim no IPP paub, VCIpp tuaj yeem siv los txiav txim siab lub zog; Yog tias qhov kwv yees ntau ntawm IPP tsis tuaj yeem txiav txim siab, nws yog qhov zoo dua los xaiv TVS lub zog siab dua. PM yog qhov siab tshaj plaws pulse power dissipation tus nqi uas TVS tuaj yeem tiv taus. Nyob rau hauv ib tug muab siab tshaj plaws clamping voltage, ntau dua lub hwj chim noj PM, ntau dua lub peev xwm ntawm nws surge tam sim no; Nyob rau hauv ib qho kev siv lub zog PM, qhov qis dua qhov clamping voltage VC, qhov ntau dua qhov muaj peev xwm tiv taus qhov hluav taws xob tam sim no. Tsis tas li ntawd, ncov pulse hwj chim noj kuj muaj feem xyuam rau pulse waveform, duration, thiab ambient kub. (5) Cov pulses ib ntus uas TVS tuaj yeem tiv taus yog tsis rov ua dua, thiab qhov ntsuas pulse repetition zaus (qhov piv ntawm lub sijhawm mus rau lub sijhawm sib nrug) ntawm lub cuab yeej yog 0.01 feem pua. Yog hais tias rov qab pulses tshwm sim nyob rau hauv lub Circuit Court, lub tsub zuj zuj ntawm mem tes zog yuav tsum tau txiav txim siab, txwv tsis pub nws yuav ua rau TVS puas.

(6) Rau kev tiv thaiv ntawm cov khoom me me tam sim no, nws muaj peev xwm ua kom paub meej ntxiv qhov txwv tam sim no rau kab. Ntev npaum li qhov kev tiv thaiv tus nqi ntawm qhov tam sim no limiting resistor yog qhov tsim nyog, nws feem ntau tsis cuam tshuam rau kev ua haujlwm ntawm cov kab, tab sis tam sim no tsim los ntawm kev cuam tshuam los ntawm qhov tam sim no limiting resistor yuav raug txo kom tsawg. Txawm li cas los xij, nws muaj peev xwm xaiv TVS cov raj uas muaj lub zog siab tshaj plaws los tiv thaiv cov kab me me tam sim no.

(7) Lub capacitance C yog txiav txim siab los ntawm ntu ntu ntawm TVS avalanche hlws ris, uas yog ntsuas ntawm qhov tshwj xeeb zaus ntawm 1 MHz. Qhov loj ntawm C yog proportional rau tam sim no withstand peev xwm ntawm lub TVS, thiab loj heev C yuav attenuate lub teeb liab. Yog li ntawd, C yog ib qho tseem ceeb parameter rau xaiv TVS rau cov ntaub ntawv interface circuits. Rau cov circuits nrog cov ntaub ntawv siab dua / cov teeb liab zaus, qhov cuam tshuam ntawm diode capacitance ntau dua ntawm lub voj voog, thiab ntau dua qhov kev siv suab nrov lossis attenuation signals. Yog li ntawd, nws yog ib qho tsim nyog los txiav txim siab qhov peev xwm ntawm cov khoom siv xaiv raws li cov yam ntxwv ntawm lub Circuit Court. Feem ntau, lub capacitance ntawm high-frequency circuits yuav tsum raug xaiv kom tsawg li tsawg tau (xws li LCTVS thiab low capacitance TVS, nrog ib tug capacitance tsis ntau tshaj 3 pF), thaum rau circuits uas tsis muaj capacitance yuav tsum tau, lub capacitance yuav xaiv saum toj no 40. pF.

(8) Yuav kom ua tau raws li IEC61000-4-2 tus qauv thoob ntiaj teb, TVS diodes yuav tsum muaj peev xwm tswj tau qhov tsawg kawg nkaus ntawm 8 kV (MB, tiv tauj) thiab 15 kV (BM, huab cua) ESD cuam tshuam. Qee cov tuam txhab lag luam semiconductor tau siv cov qauv kev tiv thaiv siab dua ntawm lawv cov khoom. Rau qee daim ntawv thov khoom siv portable nrog cov kev cai tshwj xeeb, cov neeg tsim qauv tuaj yeem xaiv cov khoom siv raws li xav tau.