Kenwood TH-22A Service Manual

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TH-22A/AT/E20e Functions of pinsSEMICONDUCTOR DATA |PinNoPincodevoFunction1OSCIN|Crystaloscillatorconnectionpinandreferencedividerinput pin3OSCourtO(OSCIN=Oscillatorcircuitinputpin,OSCouT=Oscillatorcircuitoutputpin)4VP-Powersupplypinforchargepumpandanalogswitchoutput5 Voc - Power supply pin6 Do O | Built-in charge pump output pin7 GND - GND pin8 LDO|Phasecomparatoroutputpin.NormallyLDishigh.LDislowintheperiodcorrespondingtothephasedifferencebetweenfrandfp.10 fin | Prescaler input pin. AC connection11Clock|Clockinputpinfor19and16-bitshiftregisters.: Data is read on the rising edge of the clock pulse.13 Data I Binary code serial data input pin. The last data bit is a control bit.Control data Serial data destinationH 15 bit latchesL 18 bit latches14LE|Loadenablesignalinputpin(withpull-upresistor).WhenLEishighoropen, theshiftregistercontentsaresentfothelatchtogetherwith theserialdatacontrolbit.Thebuilt-inanalogswitchturnson,andtheoutputsignalfromthebuilt-inchargepumpissenttotheBiSWpin.15FC|Phase comparator phaseswitchingpin(withpull-upresistor).Thisreversesthepolarity ofthephasecomparatoroutputaccordingtothepolarityofthe externallyconnectedLPFand VCO.WhenFCislow,thecharacteristicsofthechargepumpandphase comparatorarereversed.Italsoswitchesbetweenfoutpin(testpin)outputsfrandfp.16BISWO|Analogswitchoutputpin.Normallyhighimpedance.Onlywhentheswitchison(LE:high),thebuilt-inchargepumpstateisoutput.17foutO|Phase comparatorinputmonitorpin. Eitherthereferencedivideroutput(fr)orcomparisondivideroutput(fp)signalisoutputaccordingtotheFCpininputlevel.FC Output signa!H fr outputL fp output18oPO|Phase comparatorexternalchargepumpoutputpin.ThephasecharacteristicsarereversedbytheFCpinsetting.20 oR O | The 6P pin is Nch, open drain output.2,9, 12, 19 -NC - | Noconnection