HT45F5N datasheet(44/202 Pages) HOLTEK

44 / 202 page

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HT45F5N/HT45FH5N

Power Bank ASSP Flash MCU

HT45F5N/HT45FH5N

Power Bank ASSP Flash MCU

Internal RC Oscillator – HIRC

TheinternalRCoscillatorisafullyintegratedsystemoscillatorrequiringnoexternalcomponents.

The internal RC oscillator has a fixed frequency of 8MHz. Device trimming during the

manufacturingprocessandtheinclusionofinternalfrequencycompensationcircuitsareusedto

ensurethattheinfluenceofthepowersupplyvoltage,temperatureandprocessvariationsonthe

oscillationfrequencyareminimised.Itrequiresnoexternalpinsforitsoperation.

Internal 32kHz Oscillator – LIRC

Theinternal32kHzSystemOscillatoristhelowfrequencyoscillator.Itisafullyintegrated

RCoscillatorwithatypicalfrequencyof32kHzat5V,requiringnoexternalcomponentsforits

implementation.Devicetrimmingduringthemanufacturingprocessandtheinclusionofinternal

frequencycompensationcircuitsareusedtoensurethattheinfluenceofthepowersupplyvoltage,

temperatureandprocessvariationsontheoscillationfrequencyareminimised.

Operating Modes and System Clocks

Presentdayapplicationsrequirethattheirmicrocontrollershavehighperformancebutoftenstill

demandthattheyconsumeaslittlepoweraspossible,conflictingrequirementsthatareespecially

trueinbatterypoweredportableapplications.Thefastclocksrequiredforhighperformancewill

bytheirnatureincreasecurrentconsumptionandofcoursevice-versa,lowerspeedclocksreduce

currentconsumption.AsHoltekhasprovidedthisdevicewithbothhighandlowspeedclock

sourcesandthemeanstoswitchbetweenthemdynamically,theusercanoptimisetheoperationof

theirmicrocontrollertoachievethebestperformance/powerratio.

System Clocks

ThedevicehasmanydifferentclocksourcesforboththeCPUandperipheralfunctionoperation.By

providingtheuserwithawiderangeofclockoptionsusingregisterprogramming,aclocksystem

canbeconfiguredtoobtainmaximumapplicationperformance.

Themainsystemclock,cancomefromeitherahighfrequencyfHorlowfrequencyfSUBsource,

andisselectedusingtheHLCLKbitandCKS2~CKS0bitsintheSMODregister.Thehighspeed

systemclockcanbesourcedfromtheHIRCoscillator.Thelowspeedsystemclocksourcecanbe

sourcedfromtheLIRCoscillator.Theotherchoice,whichisadividedversionofthehighspeed

systemoscillatorhasarangeoffH/2~fH/8.

HT45F5N Datasheet(PDF) 44 Page - Holtek Semiconductor Inc