 |
поискавой системы для электроныых деталей |
|
|
поискавой системы для электроныых деталей |
|
HT7L2102 датащи(PDF) 5 Page - Holtek Semiconductor Inc |
|
|
|||||||||||||||||||||||||||||
HT7L2102 датащи(HTML) 5 Page - Holtek Semiconductor Inc |
|
|
5 / 11 page  Rev. 1.00 5 November 4, 2011 HT7L2102 Application Information Operation Overview TheHT7L2012isahighlyfunctionallyintegrated PWMcontrollerforLEDlightingandisoptimizedto restrictEMI.Thedeviceofferadimmingprecisionof lessthan1%andhasadimmingrangeof1%to99%. ItsintegratedfeaturesincludeGreenmode(Non- Acoustic-Noise),internalslopecompensation,high efficiencyunderdifferentloadconditionswithina wideoperatingtemperaturerangeof-40°Cto85°C. The devices also includes a range of protection functions,SCP,OVP,UVLO,currentlimit,LEB, softstart,OTPforexternalthermistorsensing.These features not only enhance system performance, butalsoensurehighstabilityofthewholecircuit application even under extreme environmental conditionssuchashightemperatureorhighEMI levels. Advanced Precision Oscillator for Green-Mode Switching and Non-Acoustic Noise Requirement ATrimmed Precision Green Mode Oscillator is implementedinthedevicetoenhancetheconversion efficiencyunderlightloadconditions.AsFig.7 shows,theefficiencydifferencebetweenlightloads andheavyloadsislessthan1%,whiletheaverage efficiencyisonly89.5%,thepeakefficiencyis90%. Figure 7 HT7L2102 Efficiency Performance between Light-Load and Heavy-Load TheGreenModeOscillatortypessuppliedbyother PWMControllerprovidersareplaguedbyAcoustic- Noiseproblems.Thisisbecause,underlightload conditions, the frequency will keep decreasing throughtheHumanAcousticRange(from20Hz to20kHz),andtheseaudiofrequenciesmaycreate audiblenoiseinthetransformer.Holtek’sHT7L2102 patentedGreenModeOscillatordesignedusingan advancedNon-AcousticNoisestructureprevents thegenerationoffrequenciesintheaudiofrequency band,thuseliminatinganytransformernoise. Figure 8. Oscillator Behavior Compared with HT7L2102 and Other Green Mode PWM Controller Frequency Jitter for EMI Restriction EMIrestrictionisaccomplishedusingaFrequency Jitterfunction,whichspreadstheenergyoverawider frequencyrangethanthebandwidthmeasuredby theEMItestequipment.AninternalFrequencyJitter circuitchangestheswitchingfrequencybetween+4% and-4%ofthecentralfrequencywithaperiodof 4ms. Figure 9 Frequency Jitter Function Spreads Energy Over a Period to Accomplish EMI Restraining |
|
|
ссылки URL |
| Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | Ссылка на техническое описание | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
Russian ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
