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FEATURESDESCRIPTION
右
d
QS
20
延迟
23
地
11
VCC
参考
15
rt
17
ct
18
同步
19
CSA−
9
CSA+
8
ss
4
CSAO
7
CEA−
13
VEA−
16
VEA+
14
22
24
3
2
1
RAMPCEA+
12
CEAOVEAO
10
拉
PGND
按压
src
降压
V+
延迟
延迟
t
q
q
参考
&放大器;
UVLO
ss
INHBT
UV
osc
500 khz
最大值
6 5
21
电流 感觉
放大器
ilim 比较器
+3 v
电流 错误
放大器
pwm 比较器0.7 v
飞行
驾驶员
按压/拉
驱动程序
osc
UVLO
v旧 错误
放大器
+
uc1827-1,uc1827-2
uc2827-1,uc2827-2
uc3827-1,uc3827-2
SLUS365A–APRIL1999–REVISEDAUGUST2005
buckcurrent/voltagefedpush-拉
PWMCONTROLLERS
•
idealformultipleoutputand/orhigh
TheUC3827familyofcontrollerdevicesprovidesan
VoltageOutputVoltageConverters
integratedcontrolsolutionforcascadedbuckand
按压-pullconverters.theseconvertersareknownas
•
Upto500kHzOperation
currentfedorvoltagefedpush-pullconvertersand
•
highvoltage,highcurrentfloating
areideallysuitedformultipleoutputand/orhigh
DriverforBuckConverterStage
voltageoutputapplications.inbothcurrentfedand
•
uc3827-1currentfedcontrollerhas
voltagefedmodes,thepush-pullswitchesaredriven
按压-pulldriverswithoverlapping
at50%nominaldutycyclesandatonehalfthe
switchingfrequencyofthebuckstage.inthecurrent
ConductionPeriods
fedmode,thetwoswitchesaredrivenwithaspeci-
•
uc3827-2voltagefedcontrollerhas
fiedover-lapperiodtopreventringingandvoltage
按压-pulldriverswithnonoverlapping
stressonthedevices.inthevoltagefedmode,这
ConductionPeriods
twoswitchesaredrivenwithaspecifiedgaptime
•
averagecurrentmode,peakcurrent
betweentheswitchestopreventshortingthetrans-
ModeorVoltageModewithInput
formeracrosstheenergystoragecapacitorandto
prohibitexcessivecurrentsflowingthroughthede-
VoltageFeedforwardControlforBuck
恶习.
PowerStage
•
widebandwidth,lowoffset,
服务器'soutputvoltageisregulatedbypulse
DifferentialCurrentSenseAmplifier
widthmodulationofthebuckswitch.theuc3827
containscompleteprotectionandpwmcontrolfunc-
•
PreciseShortCircuitCurrentControl
tionsforthebuckconverter.easycontrolofthe
floatingswitchisaccomplishedbythefloatingdrive
电路.thegatedrivewaveformislevelshiftedto
supportaninputvoltageupto72V
直流
.
BLOCKDIAGRAM
pleasebeawarethatanimportantnoticeconcerningavailability,标准保修,anduseincriticalapplicationsoftexas
instrumentssemiconductorproductsanddisclaimerstheretoappearsattheendofthisdatasheet.
productiondatainformationiscurrentasofpublicationdate.
copyright©1999–2005,texasinstrumentsincorporated
ProductsconformtospecificationsperthetermsoftheTexas
instrumentsstandardwarranty.productionprocessingdoesnot
必要包括测试所有参数.
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