Maxon Telecom SP210 Pll Ic, Out-of-Lock Detector, Charge Pump and Loop Filter, DC to DC Converter

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Maxon SP200/210 Radio

SP200/210

In transmit the VCO has modulation from the audio processing circuitry applied to D202. C204 is used to provide compensation for non-linearity caused by the modulation diode and maintains a constant modulation regardless of the frequency of operation.

PLL IC

The reference frequency from the TCXO, at 12.8 MHz, is connected to pin 20 of IC2 (MC145191). The appropriate VCO is connected to pin 11.

The external reference frequency, TCXO input, is divided by the reference divider (REFDIV), which is set to divide by 2048 for 12.5kHz or 25kHz channels (6.25kHz) or to divide by 2560 for 20kHz channels (5kHz). This is known as the reference frequency, Fr.

The comparison frequency is determined by the settings which are stored within the EEPROM (IC404). Choice of these comparison frequencies means that the minimum step size of the synthesiser is either 5kHz or 6.25kHz and therefore, 12.5kHz, 20kHz and 25kHz channel spacings can be accommodated.

IC2 is programmed on pin 19, to obtain the desired frequency, by serial data from the microcontroller (IC403 pin 21). IC2 Pin 19 is the data input and pin 18 is the clock input and pin 17 is the PLL enable line.

The VCO frequency, Fin, is divided down by the programmable divider (64/65 prescaler VARDIV) to, again, produce 5kHz or 6.25kHz. This frequency is known as the variable frequency, Fv.

In the phase/frequency comparator, the phase difference between the reference frequency, Fr, and the VCO signal, Fv, is compared.

When Fv = Fr, the phase detector output (pins 3 and 4, IC2) produces narrow negative pulses and Fv and Fr pulse widths are identical. When Fv > Fr, pin 4 (V) pulses negative, with pin 3 (R) remaining high. When Fv < Fr, pin 3 (R) pulses negative with pin 4 (V) remaining high. The signal at pins 3 and 4 is smoothed by the loop filter and applied to the VCO.

Out-of-Lock Detector

The out-of-lock detector output remains essentially high with narrow low-going pulses when in lock. The output pulses low when Fr and Fv are out of phase or at a different frequency (results in wider pulses). These pulses at pin 2 are buffered by Q5 and then integrated by R1 and C11. The resultant voltage is fed to the microcontroller, IC403, pin 53.

IC2 has two output ports:

Port A pin 16 Configurable digital port, which is used as tx enable 2, which controls the application of volts to the PA stage.

Port B pin 15 Open drain digital output, which is used as a power save control.

Pin 13 labelled test2 allows the technician to see the output of the dual modules prescaler for trouble shooting purposes, no connection should be made to this pin.

Charge Pump and Loop Filter

Transistors Q6 to Q8 and Q11, and associated components, form the charge pump. The phase detector output from IC2 pins 3 and 4 are combined by the charge pump to produce a 0 to 12V tuning voltage.

The voltage signal is filtered by the loop filter (R12 – R14, C21 - C24) to remove harmonics of the reference frequency.

DC to DC Converter

The DC to DC converter, converts the +7.5 V to a 16 V suppy. This is used to provide the tuning voltage for the VCO. A wide voltage range is required to allow for the wideband operation of the radio.

Q904, Q905 and associated components, form a 200kHz oscillator. The output of the oscillator is rectified (voltage tripled) by D901, D902 and D903. C901, C902 and C916 provide filtering. The resultant 16Vdc is passed to R909 and then becomes the supply rail for the charge pump.

DETAILED FUNCTIONAL DESCRIPTION

Issue 1.0

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03/01

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Contents SP200/210 NSW Australia Tel +61 0 2 9707 Amendment Record Sheet Issue No Effective Date Reason for Change SignatureAmendment Record Sheet Maxon SP200/210 Radio Table of Contents 10-1 SL100 UHF Parts List11.4 Default Settings 11-8 11-1List of Tables Maxon SP200/210 Radio Issue 03/01 Amendments to this Manual Using this ManualIntroduction Category C Engineering BulletinContact Information Specifications GeneralVibration Environmental Operating Temperature RangePhysical Dimensions Synthesiser ESD EMCPre-Install Check Accessories Accessories & OptionsOptions Accessories & Options INSTALLATION, Commissioning & Alignment INSTALLATION, Commissioning & AlignmentInstallation ConnectionsCommissioning Recommended Test EquipmentCommissioning Equipment Commissioning KitTest Equipment Set-up using Discrete Test Equipment Discrete Test EquipmentSK 3100 Service Kit Transmitter Performance Tests Test Equipment ConnectionReceiver Performance Tests Squelch Power AdjustmentAudio Output Preparation Tests without DisassemblyAlignment VHFRemoving and Replacing Battery Disassembly and Re-assembly of the RadioRemoving and Replacing the Belt Clip Location of Adjustment Points Removing and Replacing the Main AssemblyPLL Alignment Transmitter Alignment Squelch SensitivityTcxo Radiocommunications Test SET Audio deviation adjustment Balance AdjustmentCtcss / DCS deviation At maximum volume, nominal distortion is 10% Audio Volume LevelReceiver Alignment Common Circuits Detailed Functional DescriptionIntroduction EepromAudio Signal Path Audio AsicSat Signal Path Miscellaneous Signals and ControllerAudio/SAT Circuits Common RF Circuits Battery Low Indicator CircuitLEDs and indicators PLL SynthesiserCharge Pump and Loop Filter PLL ICOut-of-Lock Detector DC to DC ConverterTransmitter Antenna SwitchAutomatic power control APC circuits PA moduleReceiver Front EndSquelch Mute Circuit First MixerSecond mixer, Second IF, FM detector 16kHz Band Pass FilterAF Output Low Pass Filter Noise detector circuitSpeaker Audio Amplifier Diagnostics TroubleshootingDiagnostic Function TroubleshootingTroubleshooting Chart If ICTransistors Main Circuit Voltage ChartsMain Circuit Transistor Voltages Integrated Circuit Voltages Receive Integrated CircuitsIntegrated Circuit Voltages Transmit Troubleshooting Troubleshooting Troubleshooting Troubleshooting Introduction ProgrammingSMP6100 Getting StartedProgram/Print/Save Select Features MenuScanning Program RadioPrint Data Save Data to DiskMaxon SP200/200 Radio SP200/210 Exploded Mechanical Drawings & Parts Lists Exploded Mechanical Drawings & Parts ListsParts List Spare PartsSL100U2 SL100V2Mechanical Parts For details on servicing, please refer to SectionParts List for Exploded Mechanical Drawing LCD TTR 1866 DpfdpwSML-020MLTT86 SMD PCB LCDSKPT-110VA NUT M7 BsbmPCB VCO PCB RF Aldc Bsbm M2.6V2 Control Circuit SL100 VHF Parts List05B-000-5Z Chip Ceramic 0.012UF GRM39 X7R123K 25V P Diode Switching KDS181S A3Chip Ceramic 0.001UF GRM39 X7R102K 50V P Chip Ceramic 0.0022UF GRM39 X7R222J 50V P2 V2 RF SW Tact SKPT-1101VAThermistor Chip 33KNTCCS32163SH333KC TH1 RES.CHIP Trimmer 1K RH03E1C13XRES.CHIP Trimmer 10K RH03E1C14X Elect Capacitor 10UF 16V 20%Chip Ceramic 43PF GRM40 COG430J 50V P RE Power Module GNOK-M68776-E01 IC9Chip Ceramic 39PF GRM40 COG390J 50V P Chip Ceramic 47PF GRM39 COG470J 50V PTcxo Assembly 4 V2 VCO 5 V2 Front EndSL100 UHF Parts List U2 Control CircuitConnector Waffer Chip Resistor 18K 2 U2 RFChip Resistor 12K Chip Resistor 39KChip Ceramic 10PF GRM40 COG100C 50V P RES.CHIP Trimmer K RH03E1C13XChip Ceramic 0.0015UF GRM39 X7R152K 50V P Chip CeramicChip Ceramic 470PF GRM40 COG471J 50V P Power Mpduleuhf M68732HGNOK IC9Chip Ceramic 2.2PF GRM40 COG2R2C 50V P Chip Ceramic 4.7PF GRM40 COG4R7C 50V PCoil Spring X0.35X7TR TcxoCoil Chip 18NHLL2012-F18NM Coil Spring 2X0.75X3TL SMD4 VCO Maxon SP200/210 Radio RF PCB Circuit Diagrams & PCB LayoutsCircuit Diagrams & PCB Layouts TcxoCircuit Diagrams & PCB Layouts Digital Board Layout Top Side Digital Board Layout Bottom Side RF Board Layout Top Side Issue RF Board Layout Bottom Side P406787a Front End Front-End Board Layout Tcxo Board Layout 10SPARE Parts Spare Parts & Maintenance Policy10.1Spare Parts Surface mount components Component ReplacementSurface mount component replacement Surface mount removalSurface mounted integrated circuit replacement Spare Parts & Maintenance Policy 11.2Test Equipment 11APPENDIX ACC-2003 Alignment BOX11.1Purpose 11.3Calibration ProgramCalibration Program Primary Screen Appendix a ACC-2003 Alignment BOXAsic Control Screen Rx TXTRIM2 Adjustment of Asic valuesTXTRIM3 RX VOL SAT Balance Transmit AdjustmentsSAT Deviation Receive Adjustments Audio Output LevelV1 Default Frequency Table 11.4Default Settings11.4.1 V1 Band Default Settings V1 Default Asic SettingsV2 Default Frequency Table 11.4.2 V2 Band Default SettingsV2 Default Asic Settings U1 Default Frequency Table 11.4.3 U1 Band Default SettingsU1 Default Asic Settings U2 Default Frequency Table 11.4.4 U2 Band Default SettingsU2 Default Asic Settings
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