參數(shù)資料
型號: UC3845
廠商: 意法半導體
英文描述: Current Mode PWM Controller(電流模式PWM控制器)
中文描述: 電流模式PWM控制器(電流模式的PWM控制器)
文件頁數(shù): 1/11頁
文件大小: 96K
代理商: UC3845
UC2842/3/4/5
UC3842/3/4/5
October 1998
CURRENT MODE PWM CONTROLLER
.
OPTIMIZED FOR OFF-LINE AND DC TO DC
CONVERTERS
.
LOWSTART-UP CURRENT (< 1 mA)
.
AUTOMATIC FEED FORWARD COMPENSA-
TION
.
PULSE-BY-PULSECURRENT LIMITING
.
ENHANCED LOAD RESPONSE CHARAC-
TERISTICS
.
UNDER-VOLTAGELOCKOUTWITHHYSTER-
ESIS
.
DOUBLEPULSESUPPRESSION
.
HIGH CURRENT TOTEM POLEOUTPUT
.
INTERNALLY TRIMMED BANDGAP REFER-
ENCE
.
500 KHz OPERATION
.
LOWR
O
ERRORAMP
DESCRIPTION
TheUC3842/3/4/5familyofcontrolICsprovidesthe
necessary features to implement off-line or DC to
DC fixed frequencycurrent mode controlschemes
witha minimalexternalpartscount.Internallyimple-
mentedcircuitsincludeundervoltagelockoutfeatur-
ingstart-up current lessthan1 mA,a precisionref-
erencetrimmedforaccuracyat theerrorampinput,
logicto insurelatchedoperation,a PWMcompara-
torwhichalsoprovidescurrentlimitcontrol,andato-
tem pole output stage designed to source or sink
high peak current. The output stage, suitable for
drivingN-ChannelMOSFETs,islowintheoff-state.
Differencesbetweenmembersof thisfamilyarethe
under-voltage lockout thresholds and maximum
dutycycle ranges.The UC3842 and UC3844 have
UVLO thresholdsof 16V (on) and 10V (off), ideally
suited off-line applications The corresponding
thresholdsfor the UC3843 and UC3845 are 8.5 V
and 7.9 V. The UC3842 and UC3843 can operate
to duty cycles approaching 100%. A range of the
zero to < 50 % is obtained by the UC3844 and
UC3845bytheadditionof aninternaltoggleflipflop
whichblanksthe outputoff every otherclock cycle.
BLOCK DIAGRAM
(toggle flip flop used only in U3844 and UC3845)
Minidip
SO14
1/11
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相關代理商/技術參數(shù)
參數(shù)描述
UC3845A 制造商:TI 制造商全稱:Texas Instruments 功能描述:Current Mode PWM Controller
UC3845A-BW 制造商:FCI 制造商全稱:First Components International 功能描述:Current Mode PWM Controller Low Start-Up and Operating Current
UC3845AD 功能描述:電流型 PWM 控制器 Current Mode RoHS:否 制造商:Texas Instruments 開關頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風格:SMD/SMT 封裝 / 箱體:TSSOP-14
UC3845AD1 功能描述:電流型 PWM 控制器 RO 511-UC3845BD 9/04 RoHS:否 制造商:Texas Instruments 開關頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風格:SMD/SMT 封裝 / 箱體:TSSOP-14
UC3845AD1013TR 制造商:STMicroelectronics 功能描述: