HT45F75 datasheet(7/190 Pages) HOLTEK

7 / 190 page

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HT45F75

Body Fat Scale Flash MCU

HT45F75

Body Fat Scale Flash MCU

General Description

ThisHoltekdeviceisspecificallydesignedforbodyfatscaleapplications.Measuringbodyfat

usesatechniquewherebyanACcurrentflowingthroughthehumanbodyismeasuredandthen

usedtocalculateabodyfatvalue.Thespecialisedcircuitstodothisareaweightmeasurement

circuitandafatmeasurementcircuit.Theweightmeasurementcircuitusesanexternalloadcellto

outputasignal,whichafteramplificationbyanOPA,andthenconversionusinganADC,readsthe

correspondingvalueasthecalculatedweight.ThefatmeasurementcircuitusesanACsignalvia

anelectrodeslicetoflowthroughhumanbody.AfteramplificationbyaninternalOPA,andthen

conversionbyanADC,themeasuredvalueisonerepresentingbodyimpedance,whichisusedto

calculatethecorrespondingbodyfatvalue.

Thedevice,whichintegratesthebodyfatscalecircuitry,isaFlashMemoryA/Dtype8-bithigh

performanceRISCarchitecturemicrocontrollerwhichincludesamulti-channel20-bitDelta-sigma

A/D(ΔΣA/D)converter,whichisdesignedforapplicationsthatinterfacedirectlytoanalogsignals

andwhichrequirealownoiseandhighaccuracyanalogtodigitalconverter.Offeringusersthe

convenienceofFlashMemorymulti-programmingfeatures,thisdevicealsoincludesawiderange

offunctionsandfeatures.OthermemoryincludesanareaofRAMDataMemoryaswellasanarea

oftrueEEPROMmemoryforstorageofnon-volatiledatasuchasserialnumbers,calibrationdata

etc.

Analogfeaturesincludeamulti-channel20-bitΔΣA/Dconverterandprogrammablegainamplifier

(PGA)functions.AnextremelyflexibleTimerModuleprovidestiming,pulsegenerationandPWM

generationfunctions.Inaddition,aninternalLDOfunctionprovidesvariouspoweroptionstothe

internalandexternaldevices.ProtectivefeaturessuchasaninternalWatchdogTimer,LowVoltage

ResetandLowVoltageDetectorcoupledwithexcellentnoiseimmunityandESDprotectionensure

thatreliableoperationismaintainedinhostileelectricalenvironments.

Afullchoiceofvariousinternalandexternaloscillatorfunctionsisprovidedincludingafully

integratedsystemoscillatorwhichrequiresnoexternalcomponentsforitsimplementation.The

abilitytooperateandswitchdynamicallybetweenarangeofoperatingmodesusingdifferent

clocksourcesgivesuserstheabilitytooptimisemicrocontrolleroperationandminimisepower

consumption.

HT45F75 датащи(PDF) 7 Page - Holtek Semiconductor Inc