User`s guide

Rev. 1.10 128 November 14, 2014 Rev. 1.10 129 November 14, 2014
HT66FW2230
Wireless Charger A/D Flash 8-Bit MCU
LVD Operation
TheLowVoltageDetectorfunctionoperatesbycomparingthepowersupplyvoltage,V
DD
,witha
pre-speciedvoltagelevelstoredintheLVDCregister.Thishasarangeofbetween2.0Vand4.0V.
Whenthepowersupplyvoltage,V
DD
,fallsbelowthispre-determinedvalue,theLVDObitwillbe
sethighindicatingalowpowersupplyvoltagecondition.TheLowVoltageDetectorfunctionis
suppliedbyareferencevoltagewhichwillbeautomaticallyenabled.Whenthedeviceispowered
downthelowvoltagedetectorwillremainactiveiftheLVDENbitishigh.AfterenablingtheLow
VoltageDetector,atimedelayt
LVDS
shouldbeallowedforthecircuitrytostabilisebeforereadingthe
LVDObit.NotealsothatastheV
DD
voltagemayriseandfallratherslowly,atthevoltagenearsthat
ofV
LVD
,theremaybemultiplebitLVDOtransitions.
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

LVD Operation
TheLowVoltageDetectoralsohasitsowninterruptwhichiscontainedwithinoneoftheMulti-
functioninterrupts,providinganalternativemeansoflowvoltagedetection,inadditiontopolling
theLVDObit.Theinterruptwillonlybegeneratedafteradelayoft
LVD
aftertheLVDObithasbeen
sethighbyalowvoltagecondition.WhenthedeviceispowereddowntheLowVoltageDetector
willremainactiveiftheLVDENbitishigh.Inthiscase,theLVFinterruptrequestagwillbeset,
causinganinterrupttobegeneratedifVDDfallsbelowthepresetLVDvoltage.Thiswillcausethe
devicetowake-upfromtheSLEEPorIDLEMode,howeveriftheLowVoltageDetectorwakeup
functionisnotrequiredthentheLVFagshouldberstsethighbeforethedeviceenterstheSLEEP
orIDLEMode.