Panasonic KX-HCM110A

AmplifierforAutoLevelControl
PCMCodec(IC601)
PowerSupplyVoltage:3.3V
ClockFrequency:Containsabuilt-inPLLfunctionandgeneratesaclockfromtheBCLK(256KHz).
Containsanamplifier,LPF,gainadjustment,AD/DAconverter,hostI/F,PCMserialI/Fandspeaker
outputfunction.
FlowofSoundSignal
[Microphonesound]
1.Thesounddatainputfrompin1ofthebuilt-inmicrophoneconnector
(CN607)isamplifiedbytheamplifierinthePCMCodec(IC601)andthe
ALC(IC603),theninputasthebuilt-inmicrophonetothePCMCodec
(IC601)again.
Whentheleveloftheinputsoundsignalismorethanthespecified
value,thegainischangedandtheoutputsignalleveliskeptconstant
attheALC(IC603).Sounddistortioniscontrolledwhentheinputis
excessive.
2.Whentheexternalmicrophoneisattachedtothemicrophonejack
(CN603),thesoundsignalinputfrompin2oftheCN603isamplifiedby
theamplifierinthePCMCodec(IC601)andtheALC(IC602),theninput
astheexternal(microphone)tothePCMCodec(IC601)again
TheALC(IC602)worksinthesamewayastheIC603.
3.InthePCMCodec(IC601),afterthesoundsignalisswitchedbetween
thebuilt-inmicrophoneandtheexternalmicrophonebyaregister
settingfromthehost,amplification,ADconversionandgain
adjustmentareperformed.
ThesamplingfrequencyoftheA/Dconversionis8kHzanditis
convertedtothePCMintheformatof8bitand law.Then,64kbps
dataareoutputtotheASIC(101)throughtheSerialI/F.
ThedatatransferoftheSerialI/FisBCLK(256kHz).
4.Thedatacompressionof32kbpsisperformedintheADPCMBlockof
theASIC(101)andthedatatransferredassounddata.
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