EFJohnson 7780 Circuit Description, Power Switching and Regulation, Synthesizer Description

Page 65

CIRCUIT DESCRIPTION

SECTION 4 CIRCUIT DESCRIPTION

127(￿￿$￿EORFN￿GLDJUDP￿RI￿WKH￿5)￿DQG￿ORJLF￿XQLWV￿LV￿ ORFDWHG￿RQ￿SDJH￿￿￿￿￿

4.1 POWER SWITCHING AND REGULATION

4.1.1 POWER SWITCHING

8QVZLWFKHG￿EDWWHU\￿YROWDJH￿LV￿DSSOLHG￿WR￿WKH￿

SRZHU￿DPSOLILHU￿PRGXOH￿DQG￿SRZHU￿FRQWURO￿FLUFXLW￿LQ￿ WKH￿5)￿XQLW￿￿2WKHUZLVH￿￿DOO￿SRZHU￿LV￿VZLWFKHG￿E\￿

3￿FKDQQHO￿026)(7V￿4￿￿￿￿DQG￿4￿￿￿￿LQ￿WKH￿ORJLF￿ XQLW￿￿7KH￿/9&&￿VXSSO\￿LV￿SURGXFHG￿E\￿4￿￿￿￿DQG￿WKH￿ 9&&￿VXSSO\￿LV￿SURGXFHG￿E\￿4￿￿￿￿￿:KHQ￿WKH￿RQ￿RII￿

VZLWFK￿LV￿WXUQHG￿RQ￿￿WKH￿RXWSXW￿RI￿VZLWFKLQJ￿WUDQVLVWRU￿ 4￿￿￿￿JRHV￿ORZ￿ZKLFK￿WXUQV￿4￿￿￿￿DQG￿4￿￿￿￿RQ￿￿7KLV￿ DSSOLHV￿VZLWFKHG￿￿￿￿￿YROWV￿WR￿￿￿YROW￿UHJXODWRUV￿,&￿￿￿￿

DQG￿,&￿￿￿￿￿WKH￿DXGLR￿DPSOLILHU￿VWDJHV￿￿DQG￿RWKHU￿SDUWV￿ RI￿WKH￿WUDQVFHLYHU￿￿

:KHQ￿WKH￿SRZHU￿VZLWFK￿LV￿WXUQHG￿RII￿￿WKH￿EDVH￿RI￿ 4￿￿￿￿LV￿SXOOHG￿ORZ￿E\￿5￿￿￿￿ZKLFK￿WXUQV￿4￿￿￿￿RII￿DQG￿ WKH￿FROOHFWRU￿JRHV￿KLJK￿￿+RZHYHU￿￿EHFDXVH￿RI￿GLRGH￿ '￿￿￿￿￿4￿￿￿￿DQG￿4￿￿￿￿GR￿QRW￿WXUQ￿RII￿XQWLO￿&￿￿￿￿

FKDUJHV￿WKURXJK￿5￿￿￿￿￿7KLV￿SURYLGHV￿D￿VOLJKW￿WXUQ￿RII￿ GHOD\￿WR￿JLYH￿WKH￿PLFURSURFHVVRU￿WLPH￿WR￿WDNH￿RYHU￿

SRZHU￿RII￿FRQWURO￿￿7KH￿PLFURSURFHVVRU￿LPPHGLDWHO\￿ GHWHFWV￿SRZHU￿WXUQ￿RII￿E\￿PRQLWRULQJ￿WKH￿2))5(4,￿ VLJQDO￿RQ￿SLQ￿￿￿￿￿,W￿WKHQ￿FKDQJHV￿WKH￿2))5(4￿RXWSXW￿ RQ￿SLQ￿￿￿￿WR￿D￿KLJK￿OHYHO￿ZKLFK￿WXUQV￿4￿￿￿￿DJDLQ￿RQ￿

XQWLO￿FXUUHQW￿VHWWLQJV￿KDYH￿EHHQ￿VDYHG￿WR￿PHPRU\￿DQG￿ RWKHU￿UHTXLUHG￿SRZHU￿GRZQ￿IXQFWLRQV￿KDYH￿EHHQ￿ SHUIRUPHG￿￿

4.1.2 5-VOLT REGULATORS (IC401, IC402)

5HJXODWRU￿,&￿￿￿￿LQ￿WKH￿ORJLF￿XQLW￿SURYLGHV￿WKH￿ ￿￿/￿￿￿9￿￿ORJLF￿VXSSO\￿￿DQG￿UHJXODWRU￿,&￿￿￿￿SURYLGHV￿ WKH￿￿￿9￿VXSSO\￿￿7KH￿￿￿9￿VXSSO\￿LV￿LQ￿WXUQ￿VZLWFKHG￿ E\￿4￿￿￿￿4￿￿￿￿WR￿SURYLGH￿WKH￿5￿9￿￿7￿9￿￿DQG￿￿￿6￿

VXSSOLHV￿￿7KHVH￿WUDQVLVWRUV￿DUH￿FRQWUROOHG￿E\￿VLJQDOV￿ IURP￿WKH￿PLFURSURFHVVRU￿￿

7KH￿ORZ￿EDWWHU\￿GHWHFW￿VLJQDO￿LV￿SURYLGHG￿E\￿D￿ YROWDJH￿GLYLGHU￿IRUPHG￿E\￿5￿￿￿￿DQG￿5￿￿￿￿￿7KHVH￿ UHVLVWRUV￿GLYLGH￿GRZQ￿WKH￿￿￿￿9￿9FF￿VXSSO\￿WR￿SURGXFH￿ WKH￿%$7,1￿VLJQDO￿WKDW￿LV￿DSSOLHG￿WR￿SLQ￿￿￿￿RI￿WKH￿

PLFURSURFHVVRU￿

4.2 SYNTHESIZER DESCRIPTION

4.2.1 INTRODUCTION

7KH￿V\QWKHVL]HU￿RXWSXW￿VLJQDO￿LV￿SURGXFHG￿E\￿D￿ 9&2￿￿9ROWDJH￿&RQWUROOHG￿2VFLOODWRU￿￿LQ￿WKH￿5)￿XQLW￿￿ 7KH￿9&2￿IUHTXHQF\￿LV￿FRQWUROOHG￿E\￿D￿'&￿YROWDJH￿ SURGXFHG￿E\￿WKH￿SKDVH￿GHWHFWRU￿LQ￿V\QWKHVL]HU￿FKLS￿ ,&￿￿￿7KH￿SKDVH￿GHWHFWRU￿VHQVHV￿WKH￿SKDVH￿DQG￿ IUHTXHQF\￿RI￿WKH￿WZR￿LQSXW￿VLJQDOV￿￿2QH￿VLJQDO￿LV￿WKH￿ UHIHUHQFH￿IUHTXHQF\￿IURP￿7&;2￿;￿￿DQG￿WKH￿RWKHU￿LV￿ IURP￿WKH￿9&2￿￿,I￿WKHVH￿VLJQDOV￿DUH￿QRW￿WKH￿VDPH￿ IUHTXHQF\￿￿WKH￿SKDVH￿GHWHFWRU￿FKDQJHV￿WKH￿9&2￿ FRQWURO￿YROWDJH￿ZKLFK￿FKDQJHV￿WKH￿9&2￿IUHTXHQF\￿ XQWLO￿ERWK￿VLJQDOV￿DUH￿V\QFKURQL]HG￿￿7KH￿9&2￿LV￿WKHQ￿ ³ORFNHG´￿RQ￿IUHTXHQF\￿￿

&KDQQHOV￿DUH￿VHOHFWHG￿E\￿SURJUDPPLQJ￿WKH￿ FRXQWHUV￿LQ￿,&￿￿WR￿GLYLGH￿E\￿GLIIHUHQW￿QXPEHUV￿￿7KLV￿

SURJUDPPLQJ￿GDWD￿FRPHV￿IURP￿WKH￿PLFURSURFHVVRU￿RQ￿ WKH￿ORJLF￿ERDUG￿￿7KH￿IUHTXHQF\￿VWDELOLW\￿RI￿WKH￿V\QWKH￿ VL]HU￿LQ￿ERWK￿WKH￿UHFHLYH￿DQG￿WUDQVPLW￿PRGHV￿LV￿GHWHU￿ PLQHG￿E\￿WKH￿VWDELOLW\￿RI￿7&;2￿;￿￿￿7KH￿VWDELOLW\￿RI￿ WKLV￿GHYLFH￿LV￿￿￿￿￿330￿IURP￿±￿￿ƒ￿WR￿￿￿￿￿ƒ￿)￿￿±￿￿ƒ￿WR￿

￿￿￿ƒ￿&￿￿￿7KH￿9&2￿RXWSXW￿VLJQDO￿LV￿EXIIHUHG￿DQG￿WKHQ￿ IHG￿WR￿WKH￿UHFHLYHU￿DV￿WKH￿ILUVW￿LQMHFWLRQ￿VLJQDO￿DQG￿WR￿

WKH￿WUDQVPLWWHU￿DV￿WKH￿WUDQVPLW￿VLJQDO￿

4.2.2 VCO (IC3), BUFFERS (Q10-Q12)

6XSSO\￿YROWDJH￿WR￿9&2￿,&￿￿LV￿IURP￿&39￿UHJX￿ ODWRU￿,&￿￿DQG￿DFWLYH￿ILOWHU￿4￿￿RQ￿WKH￿,)￿ERDUG￿￿4￿￿

IXQFWLRQV￿DV￿D￿FDSDFLWDQFH￿PXOWLSOLHU￿WR￿SURYLGH￿ ILOWHULQJ￿RI￿WKH￿￿￿YROW￿VXSSO\￿WR￿WKH￿9&2￿￿5￿￿DQG￿]HQHU￿ GLRGH￿'￿￿SURYLGH￿ELDV￿￿DQG￿&￿￿SURYLGHV￿WKH￿FDSDFL￿ WDQFH￿WKDW￿LV￿PXOWLSOLHG￿￿,I￿D￿QRLVH￿SXOVH￿RU￿RWKHU￿

YROWDJH￿FKDQJH￿DSSHDUV￿RQ￿WKH￿FROOHFWRU￿￿WKH￿EDVH￿ YROWDJH￿GRHV￿QRW￿FKDQJH￿EHFDXVH￿RI￿&￿￿DQG￿'￿￿￿7KHUH￿ IRUH￿￿LW￿GRHV￿QRW￿DSSHDU￿RQ￿WKH￿HPLWWHU￿￿

7KH￿9&2￿FRQWURO￿YROWDJH￿LV￿DSSOLHG￿WR￿SLQ￿￿￿RI￿ ,&￿￿￿DQG￿WKH￿WUDQVPLW￿DXGLR￿GDWD￿PRGXODWLRQ￿VLJQDO￿LV￿ DSSOLHG￿WR￿SLQ￿￿￿￿7KH￿PRGXODWLRQ￿VLJQDO￿LV￿DOVR￿DSSOLHG￿ WR￿WKH￿7&;2￿DV￿GHVFULEHG￿LQ￿WKH￿QH[W￿VHFWLRQ￿￿7KH￿ RXWSXW￿VLJQDO￿RI￿WKH￿9&2￿RQ￿SLQ￿￿￿LV￿DSSOLHG￿WR￿D￿

7￿VSOLWWHU￿IRUPHG￿E\￿5￿￿￿5￿￿￿￿7KLV￿QHWZRUN￿URXWHV￿WKH￿ 9&2￿VLJQDO￿WR￿EXIIHU￿DPSOLILHUV￿4￿￿￿4￿￿￿DQG￿DOVR￿WR￿ 4￿￿￿￿7KHVH￿VWDJHV￿SURYLGH￿DPSOLILFDWLRQ￿DQG￿LVRODWH￿

 

November 1999

4-1

Part No. 001-7780-500

Page 64 Page 66
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Page 64 Page 66
Contents 7780 Page Page Table of Contents Table of Contents CONT’D List of Figures List of TablesScope of Manual Equipment Description General InformationFactory Customer Service AccessoriesPart Number Breakdown Transceiver IdentificationAccessory AccessoriesToll-Free 800 Factory ReturnsDefinitions Replacement PartsInternet Home Intrinsically Safe Information Possible Ignition Sources Temperature Code T3CIntrinsically Safe and Nonincendive Ratings Classification of Hazardous Areas and AtmospheresMaterial Classification Accessing PC BoardsTypical Hazard Group Class Area ClassificationRemoving Logic Unit Removing RF UnitGeneral SpecificationsControls and Display FeaturesTransceiver Operation Low-Battery Indicator Amber TX Indicator Red Indicates when the transmitter is keyedDisplay DisplayFront Panel Keys Full Keypad Model Option Switches Turning Power on and Setting VolumeGeneral Operation BacklightSee Option Switch FunctionsFunction Conv Scanning Tone ENABLE/DISABLEConventional and SMARTNET/ Smartzone Operation Monitoring Before Transmitting Conventional FeaturesDisplay Mode Selection Call Guard Squelch Monitor ModeBusy Channel Lockout Conversation Timer Penalty TimerPower Output Select Conventional Mode ScanningPriority Channel Sampling Standard Conventional Calls DTMF/ANI SignalingViewing Unit ID SMARTNET/SMARTZONE FeaturesStandard Group Calls Enhanced Private Conversation CallsTransceiver Operation Private Conversation II Calls Telephone Calls Call Alert Sending Status Conditions Emergency Alarm and CallMessaging Dynamic Regrouping Failsoft OperationSMARTNET/SMARTZONE Scanning Supervisory Tones Zone Change Parameter Keypad ProgrammingMenu Description Channel Parameters Channel Change ParameterSystem Parameters Pctrunk Software Installation Programming SetupTransceiver Programming Computer DescriptionStarting and Exiting Connecting RPI to Computer and TransceiverProgramming File Types Help FilesProgramming Procedure Screen Pop-Up Buttons and File Size IndicatorFile Size Indication Creating and Displaying SystemsMenu Bar Menu CommandsDownload Menu Upload Menu Radio Type MenuSystems Menu Window MenuRADIO-WIDE Parameter Screens DefaultsBand ZonesRadio-Wide Scan List Screen Radio Wide Scan ListModify List Screen Assign Function ButtonsRADIO-WIDE SMARTNET/SMARTZONE Screen RADIO-WIDE Conventional ScreenFull Spectrum CC Scan Hot DtmfRADIO-WIDE Portable Options Screen Adjustable ParametersProgramming Conventional Systems and Channels Conventional System General ScreenConventional System Modify Scan List Screen TimersKeypad Editing Scan List ButtonPriority Channel Selection Scan TimersSetting UP Conventional Channels Selected Channel Conventional Channel Screen ParametersSignaling Transmit PowerChannel Type Tx Time-OutTime-Out Timer Restricted AccessISW Delay Time Splinter ChannelsSMARTNET/SMARTZONE System Phone Interconnect Screen SMARTNET/SMARTZONE System Other ID’S ScreenPhone Interconnect Private CallEmergency Alarm SMARTNET/SMARTZONE System Emergency Settings ScreenSMARTNET/SMARTZONE System Talk Groups Screen Failsoft ChannelMessage Aliasing Screen SMARTNET/SMARTZONE System Lists ScreensTrunking Phone List Screen Control Channels Screen Announcement Groups ScreenTrunking Call List Screen SMARTNET/SMARTZONE Channel Screen Parameters Setting UP SMARTNET/SMART- Zone ChannelsStatus Aliasing Screen Other Screen Parameters SMARTNET/SmartZone Channel ScreenRecommended Tone Call Guard Codes Freq Call Guard CTCSS/DCS Codes and TonesMHz Channels MHz Channels MHz Channels MHz Channels MHz Channels MHz Channels Power Switching Power Switching and RegulationCircuit Description Synthesizer DescriptionCharge Pump Q1, Q2, Loop Filter VCO and Tcxo ModulationSynthesizer Chip IC1 If Amplifier Q2, LIMITER/DETECTOR IC3 Receiver Circuit DescriptionRF Amplifier Q1, First Mixer Q2 Squelch Circuit IC4A/B, IC5A Antenna Switch and LOW-PASS FilterTransmitter Description Amplifier Q9, Driver Q8Receive Audio Processing Control Logic and DisplayPin Port Name Input or Description Active High Output Microprocessor IC306 Pin DescriptionsHvfulswlrq Receive Data FILTER/DETECTOR IC102A/B, IC107A/B Audio Amplifier IC104-IC106Receive and Transmit Data Processing Transmit Audio Processing Transmit Data Filter IC206B/ IC206ASmartnet Data Processing LOW-PASS Filter IC205A/BBattery Pack Battery Pack and Charger InformationPower Setting Operating Time Function Fahrenheit CelsiusBattery Pack and Charger Information Test Setup Alignment Procedure and Performance TestsMm/3/32 Mm/1/8 Phone Jack Tune Software HqhudoMain Pctune Screen Preliminary SetupTransmit Power Adjustment Screen Transmit Frequency and PowerHigh Power Level = 3.0 watts Low Power Level = 1.0 watt Modulation BalanceRssi Adjust Squelch AdjustAudio Deviation Data DeviationReceiver Performance Tests Performance TestsTransmitter Performance Tests Power OutputTransmit Frequency Transmit ModulationThis page intentionally left blank Display Assembly Parts ListChassis Parts Ref No DescriptionDisplay Assembly KEY AssemblyIf Assembly If AssemblyKEY Assembly RF Unit PLL AssemblyRF Unit NJM2904V-TE1 IC RF Unit Logic Unit Logic Unit TDA7233D IC Logic Unit 200K ERJ3GE MP35 MP18 MP25 EP2 KEY Front PanelEP1 MP32 MP33 MP27 MP34 MP28 MP29 MP23 MP22 MP30 MP24 MP26 MP18 PLL Board Bottom View Schematic Diagrams and Component LayoutsPLL Board TOP View If Board Bottom View If Board TOP ViewRF Unit Transceiver Block DiagramMIC RF Board TOP ViewIf AMP RF Board SchematicHD1 Logic Board TOP ViewReceive Audio Processing Logic Board SchematicGND KEYR3 KEYR2 KEYR1 KEYR0 KEYS3 KEYS2 KEYS1 KEYS0 GND Display Board Bottom ViewDS3 DS4 DS5 Display Board SchematicKEY Board Back View KEY Board Front ViewS S R R R R KEY Board SchematicScan HC2 HC7 HC8 HC3 Schematic Diagrams and Component Layouts
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