Dab tsi yog qhov kev sib raug zoo ntawm kev hloov hluav taws xob hloov hluav taws xob thiab kev poob qis ntawm diodes?

Ib, Lub cev qhov tseem ceeb ntawm kev poob qis rau pem hauv ntej: tus nqi zog ntawm cov cab kuj
Lub ntsiab lus ntawm kev poob qis ntawm lub diode yog qhov tsawg kawg nkaus voltage yuav tsum tau kov yeej lub peev xwm sab hauv ntawm lub semiconductor. Rau silicon-raws li PN hlws ris diodes, cov tsim - nyob rau hauv hluav taws xob teb tsim los ntawm cov cab kuj diffusion nyob rau hauv lub P thiab N cheeb tsam yuav tsum tau ib tug voltage ntawm li 0.6-0.7V kom tsis muaj zog, cia electrons thiab qhov recombine thiab tsim ib tug tam sim no. Thiab Schottky diodes bypass PN hlws ris lub recombination mechanism los ntawm ib tug hlau semiconductor hu qauv, txo lub peev xwm barrier rau 0.2-0.4V. Qhov kev sib txawv ntawm cov qauv no ncaj qha ua rau qhov sib txawv hauv kev ua haujlwm poob ntawm ob hom diodes.

Noj 3.3V / 3A kauj ruam- nqes fais fab mov raws li piv txwv, yog siv cov silicon diode (V_F=0.8V), qhov poob hauv theem freewheeling nce mus txog 1.74W, suav txog 17.4% ntawm cov zis hluav taws xob; Los ntawm kev siv Schottky diodes (V_F=0.4V) hloov, qhov poob yog halved rau 0.87W. Qhov kev poob no tau nthuav dav ntxiv nyob rau hauv siab tam sim no thiab siab - daim ntawv thov zaus: nyob rau hauv 20A photovoltaic inverter scenario, qhov sib txawv ntawm qhov hluav taws xob poob ntawm 0.3V thiab 0.7V tuaj yeem tsim lub zog siv qhov sib txawv ntawm 8W, ncaj qha txiav txim siab qhov loj ntawm lub dab dej kub thiab lub zog txuag hluav taws xob.

2, Peb txoj kev cuam tshuam loj ntawm kev poob siab ntawm kev hloov pauv ntawm lub zog
1. Linear amplification nyhuv ntawm conduction poob
Nyob rau hauv siab tam sim no, tsawg lub luag hauj lwm voj voog scenarios, qhov kev poob no yuav ua tau kom loj hlob. Piv txwv li, nyob rau hauv asynchronous Buck circuits, lub sij hawm ua hauj lwm ntawm lub freewheeling diode tuaj yeem suav txog ntau dua 70%, thiab qhov me me ntawm V_F tuaj yeem ua rau muaj kev hloov pauv zoo hauv kev ua haujlwm. Cov ntaub ntawv tshawb fawb ntawm cov khoom siv hluav taws xob hauv kev lag luam qhia tau hais tias kev hloov cov raj rectifier thib ob los ntawm kev rov qab sai sai (V_F=1.1V) nrog ob npaug ntawm Schottky diode (V_F=0.5V) txo qis conduction los ntawm 5.8W thiab nce efficiency ntawm 83% mus rau 89.5%.

2. Cov tshuaj tiv thaiv kab mob ntawm thermal tswj
Lub conduction poob los ntawm pem hauv ntej voltage poob yuav hloov mus rau hauv tshav kub, ua rau ntaus ntawv kub thiab tsim ib tug vicious voj voog:

Kub nce → V_F txo → tam ​​sim no nce → ntau cua sov tsim → kub nce ntxiv intensifies
Qhov no thermal runaway phenomenon yog tshwj xeeb tshaj yog txaus ntshai thaum ntau cov kav dej txuas nrog nyob rau hauv parallel. Piv txwv li, ib qho IoT davhlau ya nyob twg siv lub pob loj Schottky diode, uas ua rau cov dej ntws ntws mus rau 200 μ A ntawm qhov kub ntawm 125 ° C, uas ua rau kev siv hluav taws xob standby ntau tshaj 20 npaug ntawm tus qauv. Cov tshuaj muaj xws li:
Parallel siv cov tsis tshua muaj kev sib koom tam sim no resistors (10-50m Ω)
Xaiv cov khoom siv kub zoo coefficient (xws li qee qhov MOSFET lub cev diodes)
Txhim kho cov cua kub dissipation tsim kom ntseeg tau tias qhov kub ntawm qhov sib txawv ntawm txhua cov yeeb nkab yog tsawg dua 10 ° C
3. Kev txwv tsis pub muaj kev sib koom ua ke
Qhov zoo ntawm qhov poob qis kuj tseem cuam tshuam qhov kev ua haujlwm ntawm lub cev los ntawm kev cuam tshuam cov khoom ntim thiab kev teeb tsa. Siv Schottky diode ntim rau hauv SOD-123 ua piv txwv, nws txoj kev sib txuas rau ib puag ncig thermal kuj (R θ JA) yog siab li 200℃C / W, thiab qhov kub siab tuaj yeem ncav cuag 40℃C ntawm 2A tam sim no. Txhawm rau tswj qhov kub thiab txias, cov kws ua haujlwm yuav tsum tau ua kom lub pob loj los yog ntxiv cov dab dej kub, uas yuav txo tau lub zog ceev thiab tsim kom muaj qhov tsis sib xws ntawm kev ua haujlwm thiab kev sib koom ua ke. Ib lub tsheb them nyiaj module optimized nws qhov layout los ntawm kev tso lub freewheeling diode ze rau lub hwj chim MOSFET, shortening txoj kev tam sim no thiab ua tau zoo txo ​​cov kab tsis kam los ntawm 30%, uas ua rau ib tug 1.5% nce nyob rau hauv lub system efficiency.

3, Txoj kev ntawm kev ua kom zoo dua qub: los ntawm kev xaiv cov khoom siv rau kev tsim qauv
1. Kev xaiv ntaus ntawv: ib qho kev hloov pauv ntawm cov ntaub ntawv thiab cov qauv
Silicon carbide (SiC) diode: Nrog nws cov yam ntxwv dav bandgap, nws ua tiav xoom rov qab rov qab (trr ≈ 0ns), thiab V_F txo qis nrog qhov kub thiab txias, uas qhia cov txiaj ntsig tseem ceeb hauv kev kub siab - ib puag ncig. Tom qab siv SiC Schottky diodes, qhov kev ua haujlwm ntawm ib qho photovoltaic inverter tshaj 98%, thiab nws tseem tuaj yeem ua haujlwm ruaj khov ntawm qhov kub thiab txias ntawm 175℃C.
Synchronous rectification technology: siv MOSFETs es tsis txhob freewheeling diodes los hloov cov conduction poob los ntawm ib tug linear kev sib raug zoo (V_F × I) mus rau ib tug square kev sib raug zoo (I ² R_DS (on)). Hauv cov xwm txheej tam sim no, qhov poob ntawm synchronous rectification tsuas yog 1/20 ntawm lub diode. Tom qab siv synchronous rectification, qhov ua tau zoo ntawm cov khoom siv hluav taws xob hluav taws xob tau nce los ntawm 85% mus rau 92%, thiab qhov kub nce siab los ntawm 25 ° C.
2. Circuit Court tsim: kev sib koom ua ke optimization ntawm topology thiab tswj
Mos switching technology: Los ntawm kev siv resonant lossis quasi resonant topology, lub diode tuaj yeem hloov mus rau hauv xoom voltage lossis xoom tam sim no, tshem tawm qhov rov qab poob. Tom qab tau txais kev hloov pauv tsim, lub diode poob ntawm LLC resonant fais fab mov raug txo los ntawm 70%, thiab qhov ua tau zoo tau txhim kho ntau dua 95%.
Adaptive Dead Zone Control: Los ntawm kev saib xyuas MOSFET lub teeb liab tsav hauv lub sijhawm tiag tiag -, dynamically kho lub sijhawm tuag hauv cheeb tsam kom tsis txhob hla kev. Tom qab siv cov thev naus laus zis no, qhov kev hloov pauv ntawm qee tus tsav lub cev muaj zog raug txo los ntawm 60%, thiab kev ua haujlwm tau zoo dua los ntawm 3%.
3. Thermal tswj: los ntawm passive tshav kub dissipation mus rau active tsim
Pob optimization: Tsawg thermal kuj pob xws li DFN thiab TO-247 yog siv los txo qhov cuam tshuam ntawm qhov kub thiab txias ntawm V_F. Ib qho kev sib txuas lus siv hluav taws xob siv DFN8 × 8 ntim kom ruaj khov TRR ntawm SiC diodes ntawm 150℃C.
Thermal simulation thiab layout optimization: Optimize ntaus ntawv layout los ntawm simulation software, shorten txoj kev tam sim no, thiab txo kab kuj. Ib qho kev lag luam hluav taws xob tau ua kom zoo dua nws qhov kev teeb tsa los ntawm kev ua kom luv ntawm qhov kev ncua deb ntawm lub freewheeling diode thiab lub zog MOSFET los ntawm 5mm mus rau 2mm, txo cov kab tsis kam los ntawm 40% thiab nce efficiency los ntawm 1.2%.