HT45FM2C datasheet(36/171 Pages) HOLTEK

36 / 171 page

Rev. 1.10

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Rev. 1.10

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HT45FM2C

Brushless DC Motor Flash Type 8-Bit MCU

HT45FM2C

Brushless DC Motor Flash Type 8-Bit MCU

Preliminar�

Internal 20MHz RC Oscillator – HIRC

TheinternalRCoscillatorisafullyintegratedsystemoscillatorrequiringnoexternalcomponents.

TheinternalRCoscillatorhasafixedfrequenciesof20MHz.Devicetrimmingduringthe

manufacturingprocessandtheinclusionofinternalfrequencycompensationcircuitsareusedto

ensurethattheinfluenceofthepowersupplyvoltage,temperatureandprocessvariationsonthe

oscillationfrequencyareminimised.Asaresult,atapowersupplyof5Vandatatemperatureof

25˚Cdegrees,thefixedoscillationfrequencyof20MHzwillhaveatolerancewithin2%.

Internal 32kHz Oscillator – LIRC

TheInternal32kHzSystemOscillatorisalowfrequencyoscillatorchoice.Itisafullyintegrated

RCoscillatorwithatypicalfrequencyof32kHzat5V,requiringnoexternalcomponentsforits

implementation.Devicetrimmingduringthemanufacturingprocessandtheinclusionofinternal

frequencycompensationcircuitsareusedtoensurethattheinfluenceofthepowersupplyvoltage,

temperatureandprocessvariationsontheoscillationfrequencyareminimised.Asaresult,ata

powersupplyof5Vandatatemperatureof25˚Cdegrees,thefixedoscillationfrequencyof32kHz

willhaveatolerancewithin10%.

Supplementary Clocks

Thelowspeedoscillator,inadditiontoprovidingasystemclocksourcearealsousedtoprovidea

clocksourcetootherdevicefunctions.ThesearetheWatchdogTimerandtheTimeBaseInterrupt.

HT45FM2C Datasheet(PDF) 36 Page - Holtek Semiconductor Inc