UC3844BD

更新时间： 2024-11-23 12:47:15

品牌	Logo	应用领域
意法半导体 - STMICROELECTRONICS		开关光电二极管控制器
页数	文件大小	规格书
15页	137K
描述
HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER

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中文翻译

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数据手册

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UC3844BD 数据手册

UC2842B/3B/4B/5B

UC3842B/3B/4B/5B

HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER

TRIMMED OSCILLATOR FOR PRECISE FRE-

QUENCY CONTROL

OSCILLATOR FREQUENCY GUARANTEED

AT 250kHz

CURRENT MODE OPERATION TO 500kHz

AUTOMATIC FEED FORWARD COMPENSA-

TION

Minidip

SO8

LATCHING PWM FOR CYCLE-BY-CYCLE

CURRENT LIMITING

INTERNALLY TRIMMED REFERENCE WITH

UNDERVOLTAGE LOCKOUT

HIGH CURRENT TOTEM POLE OUTPUT

UNDERVOLTAGE LOCKOUT WITH HYSTER-

ESIS

comparatorwhichalsoprovidescurrentlimitcontrol,

and a totem pole output stage designed to source

orsinkhighpeakcurrent.Theoutputstage,suitable

for driving N-Channel MOSFETs, is low in the off-

state.

LOW START-UPAND OPERATINGCURRENT

Differencesbetween members of this family are the

under-voltagelockoutthresholdsandmaximum duty

cycle ranges. The UC3842B and UC3844B have

UVLO thresholds of 16V (on) and 10V (off), ideally

suitedoff-lineapplicationsThecorrespondingthresh-

oldsfortheUC3843BandUC3845Bare8.5Vand7.9

V. The UC3842B and UC3843B can operateto duty

cycles approaching100%. A range of the zero to <

50 % is obtainedby the UC3844Band UC3845Bby

theadditionofan internaltoggleflipflopwhichblanks

theoutputoff everyotherclock cycle.

DESCRIPTION

TheUC384xBfamilyofcontrolICsprovidesthenec-

essary features to implement off-line or DC to DC

fixedfrequencycurrent modecontrol schemes with

a minimal external parts count. Internally imple-

mentedcircuits includea trimmed oscillator for pre-

cise DUTY CYCLE CONTROL under voltagelock-

outfeaturingstart-upcurrentlessthan0.5mA,a pre-

cision reference trimmed for accuracy at the error

ampinput,logicto insurelatchedoperation,a PWM

BLOCK DIAGRAM (toggle flip flop used only in UC3844B and UC3845B)

UVLO

34V

REF

VREF

5V 50mA

S/R

GROUND

INTERNAL

BIAS

2.50V

VREF GOOD

LOGIC

OUTPUT

RT/CT

OSC

ERROR AMP.

VFB

PWM

LATCH

COMP

CURRENT

SENSE

UC3842B

CURRENT

SENSE

COMPARATOR

D95IN331

1/15

March 1999

12 3 4 5 6 7...15

中文翻译

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与UC3844BD相关器件

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UC3844BD1	STMICROELECTRONICS	获取价格	HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER
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UC3844BD1013TR	STMICROELECTRONICS	获取价格	电流模式PWM
UC3844BD1G	ONSEMI	获取价格	HIGH PERFORMANCE CURRENT MODE CONTROLLERS
UC3844BD1R2	ONSEMI	获取价格	HIGH PERFORMANCE CURRENT MODE CONTROLLERS
UC3844BD1R2	MOTOROLA	获取价格	1 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO8, PLASTIC, SO-8
UC3844BD1R2G	ONSEMI	获取价格	HIGH PERFORMANCE CURRENT MODE CONTROLLERS
UC3844BDG	ONSEMI	获取价格	High Performance Current Mode Controllers
UC3844BDR2	ONSEMI	获取价格	HIGH PERFORMANCE CURRENT MODE CONTROLLERS
UC3844BDR2G	ONSEMI	获取价格	HIGH PERFORMANCE CURRENT MODE CONTROLLERS