MC1648_Motorola_elenota.pl 电路图.pdf

《MC1648_Motorola_elenota.pl 电路图.pdf》由会员分享，可在线阅读，更多相关《MC1648_Motorola_elenota.pl 电路图.pdf（11页珍藏版）》请在收音机爱好者资料库上搜索。

1、? SEMICONDUCTOR TECHNICAL DATA 1 REV 2 Motorola, Inc. 1997 1/97 ? ? ? ? ? ? ? ? The MC1648 requires an external parallel tank circuit consisting of the inductor (L) and capacitor (C). For Maximum Performance QL 100 at Frequency of Operation. A varactor diode may be incorporated into the tank circuit

2、 to provide a voltage variable input for the oscillator (VCO). The MC1648 was designed for use in the Motorola PhaseLocked Loop shown in Figure 9. This device may also be used in many other applications requiring a fixed or variable frequency clock source of high spectral purity. (See Figure 2) The

3、MC1648 may be operated from a +5.0Vdc supply or a 5.2Vdc supply, depending upon system requirements. NOTE: The MC1648 is NOT useable as a crystal oscillator. Pinout: 14Lead Package (Top View) 131412111098 2134567 VCCNCTANKNCBIASNCVEE VCCNCOUTNCAGCNCVEE Pin assignment is for DualinLine Package. For P

4、LCC pin assignment, see the MC1648 NonStandard Pin Conversion Table below. MC1648 NONSTANDARD PIN CONVERSION DATA PackageTANKVCCVCCOUTAGCVEEVEEBIAS 8 D12345678 14 L,P12141357810 20FN1820248101214 *NOTE All unused pins are not connected. Supply VoltageGND PinsSupply Pins +5.0Vdc7,81,14 5.2Vdc1,147,8

5、5 AGC LOGIC DIAGRAM 3 TANK 12 BIAS POINT 10 OUTPUT Input Capacitance = 6.0pF (TYP) Maximum Series Resistance for L (External Inductance) = 50 (TYP) Power Dissipation = 150mW (TYP)/Pkg (+5.0Vdc Supply) Maximum Output Frequency = 225MHz (TYP) VCC1 = Pin 1 VCC2 = Pin 14 VEE = Pin 7 ? VOLTAGE CONTROLLED

6、 OSCILLATOR FN SUFFIX 20LEAD PLCC PACKAGE CASE 77502 L SUFFIX 14LEAD CERAMIC PACKAGE CASE 63208 P SUFFIX 14LEAD PLASTIC PACKAGE CASE 64606 D SUFFIX 8PIN PLASTIC SOIC PACKAGE CASE 75105 Not Recommended for New Designs RadioFans.CN 收音机爱 好者资料库 MC1648 MOTOROLAHIPERCOMM BR1334 Rev 4 2 Figure 1. Circuit S

7、chematic 5 AGC 8 VEE 12 TANK 10 BIAS POINT 7 VEE1 VCC2 14 VCC1 1 Q4 Q3Q2 Q1 Q5 D1 Q8 Q7Q6 Q9 Q10Q11 D2 3 OUTPUT TEST VOLTAGE/CURRENT VALUES Test Temperature (Volts)mAdc Temperature VIHmaxVILminVCCIL MC1648 30C+2.0+1.5+5.05.0 +25C+1.85+1.35+5.05.0 +85C+1.7+1.2+5.05.0 Note: SOIC “D” package guaranteed

8、 30C to +70C only ELECTRICAL CHARACTERISTICS (Supply Voltage = +5.0V) 30C+25C+85C SymbolCharacteristicMinMaxMinMaxMinMaxUnitCondition IEPower Supply Drain Current41 mAdcInputs and outputs open VOHLogic “1” Output Voltage3.9554.1854.044.254.114.36VdcVILmin to Pin 12, IL Pin 3 VOLLogic “0” Output Volt

9、age3.163.43.23.433.223.475VdcVIHmax to Pin 12, IL Pin 3 VBIAS1Bias Voltage1.61.91.451.751.31.6VdcVILmin to Pin 12 MinTypMaxMinTypMaxMinTypMaxUnitCondition VPPPeaktoPeak Tank Voltage400mVSee Figure 3 VdcOutput Duty Cycle50% fmax2Oscillation Frequency225200225225MHz 1. This measurement guarantees the

10、dc potential at the bias point for purposes of incorporating a varactor tuning diode at this point. 2. Frequency variation over temperature is a direct function of the C/ Temperature and L/ Temperature. RadioFans.CN 收音机爱 好者资料库 MC1648 HIPERCOMM BR1334 Rev 4 3MOTOROLA Figure 2. Spectral Purity of Sign

11、al Output for 200MHz Testing B.W. = 10 kHz Center Frequency = 100 MHz Scan Width = 50 kHz/div Vertical Scale = 10 dB/div 0.1F 1200* CL 10 12 5 0.1F 3 SIGNAL UNDER TEST 10F0.1F 114 L=40nH C=10pF +5.0Vdc L: Micro Metal torroid #T2022, 8 turns #30 Enameled Copper wire. C = 3.035pF *The 1200 ohm resisto

12、r and the scope termination impedance constitute a 25:1 attenuator probe. Coax shall be CT07550 or equivalent. TEST VOLTAGE/CURRENT VALUES Test Temperature (Volts)mAdc Temperature VIHmaxVILminVEEIL MC1648 30C3.23.75.25.0 +25C3.353.855.25.0 +85C3.54.05.25.0 Note: SOIC “D” package guaranteed 30C to +7

13、0C only ELECTRICAL CHARACTERISTICS (Supply Voltage = 5.2V) 30C+25C+85C SymbolCharacteristicMinMaxMinMaxMinMaxUnitCondition IEPower Supply Drain Current41 mAdcInputs and outputs open VOHLogic “1” Output Voltage1.0450.8150.960.750.890.64VdcVILmin to Pin 12, IL Pin 3 VOLLogic “0” Output Voltage1.891.65

14、1.851.621.831.575VdcVIHmax to Pin 12, IL Pin 3 VBIAS1Bias Voltage3.63.33.753.453.93.6VdcVILmin to Pin 12 MinTypMaxMinTypMaxMinTypMaxUnitCondition VPPPeaktoPeak Tank Voltage400mVSee Figure 3 VdcOutput Duty Cycle50% fmax2Oscillation Frequency225200225225MHz 1. This measurement guarantees the dc potent

15、ial at the bias point for purposes of incorporating a varactor tuning diode at this point. 2. Frequency variation over temperature is a direct function of the C/ Temperature and L/ Temperature. RadioFans.CN 收音机爱 好者资料库 MC1648 MOTOROLAHIPERCOMM BR1334 Rev 4 4 Figure 3. Test Circuit and Waveforms 0.1F

16、1200 CL 10 12 0.1F 3 * VCC * * 5 VEE QL 100 *Use high impedance probe (1.0 Megohm must be used). * The 1200 ohm resistor and the scope termination impedance constitute a 25:1 attenuator probe. Coax shall be CT07050 or equivalent. *Bypass only that supply opposite ground. 50% ta tb VPP PRF = 1.0MHz D

17、uty Cycle (Vdc) ta tb 78 114 0.1F0.1F * OPERATING CHARACTERISTICS Figure 1 illustrates the circuit schematic for the MC1648. The oscillator incorporates positive feedback by coupling the base of transistor Q6 to the collector of Q7. An automatic gain control (AGC) is incorporated to limit the curren

18、t through the emittercoupled pair of transistors (Q7 and Q6) and allow optimum frequency response of the oscillator. In order to maintain the high Q of the oscillator, and provide high spectral purity at the output, transistor Q4 is used to translate the oscillator signal to the output differential

19、pair Q2 and Q3. Q2 and Q3, in conjunction with output transistor Q1, provides a highly buffered output which produces a square wave. Transistors Q9 and Q11 provide the bias drive for the oscillator and output buffer. Figure 2 indicates the high spectral purity of the oscillator output (pin 3). When

20、operating the oscillator in the voltage controlled mode (Figure 4), it should be noted that the cathode of the varactor diode (D) should be biased at least “2” VBE above VEE (1.4V for positive supply operation). When the MC1648 is used with a constant dc voltage to the varactor diode, the output fre

21、quency will vary slightly because of internal noise. This variation is plotted versus operating frequency in Figure 5. Figure 4. The MC1648 Operating in the Voltage Controlled Mode 0.1F L 10 12 C2 3 5 QL 100 Output Vin C1 D 1.010 1060 60100 f MHz Figure 5. Noise Deviation Test Circuit and Waveform 1

22、00 1 f, OPERATING FREQUENCY (MHz) VCC = 5 Vdc f, FREQUENCY DEVIATION, RMS (Hz) 10 1 10100 Frequency Deviation? (HP5210A output voltage) (Full Scale Frequency) 1.0Volt MV2115 MV2115 MV2106 D 100 2.3 0.15 L H Oscillator Tank Components (Circuit of Figure 4) BW=1.0kHz Frequency Meter HP5210A or Equiv V

23、oltmeter RMS HP3400A or Equiv MC1648 Frequency (f) MC1648 Under Test Attenuator Product Detector Signal Generator HP608 or Equiv 10mV20kHz 300mV20kHz above MC1648 Frequency MC1648 HIPERCOMM BR1334 Rev 4 5MOTOROLA *The 1200 ohm resistor and the scope termination impedance consti- tute a 25:1 attenuat

24、or probe. Coax shall be CT07050 or equivalent. NOT used in normal operation. * Input resistor and cap are for test only. They are NOT necessary for normal operation. *The 1200 ohm resistor and the scope termination impedance consti- tute a 25:1 attenuator probe. Coax shall be CT07050 or equivalent.

25、NOT used in normal operation. * Input resistor and cap are for test only. They are NOT necessary for normal operation. Figure 6 Figure 7 Figure 8 Vin, INPUT VOLTAGE (VOLTS) Vin, INPUT VOLTAGE (VOLTS) 18 0 8 10 190 50 64 0 Vin, INPUT VOLTAGE (VOLTS) 8 10 56 48 40 32 24 16 2468 fout, OUTPUT FREQUENCY

26、(MHz)fout, OUTPUT FREQUENCY (MHz)fout, OUTPUT FREQUENCY (MHz) 16 14 12 10 2468 0102468 170 150 130 110 90 70 0.1F L 10 12 0.1F 3 5 VCC1 = VCC2 = +5.0Vdc VEE1 = VEE2 = GND fout Vin MV1401 1200* 5.0F L = 0.13H QL 100 L: Micro Metal Toroidal Core #T4410, 4 turns of No. 22 copper wire. 0.1F L 10 12 0.1F

27、 3 5 VCC1 = VCC2 = +5.0Vdc VEE1 = VEE2 = GND fout Vin MV1401 1200* 5.0F QL 100 C = 500pF L = 1.58H L: Micro Metal Toroidal Core #T4410, 20 turns of No. 22 copper wire. C 1.0k 1.0k *The 1200 ohm resistor and the scope termination impedance consti- tute a 25:1 attenuator probe. Coax shall be CT07050 o

28、r equivalent. NOT used in normal operation. * Input resistor and cap are for test only. They are NOT necessary for normal operation. 0.1F L 10 12 0.1F 3 5 VCC1 = VCC2 = +5.0Vdc VEE1 = VEE2 = GND fout Vin 1200* QL 100 L = 0.065H L: Micro Metal Toroidal Core #T3012, 6 turns of No. 22 copper wire. 51k

29、MV1404 5.0F * * * * * * MC1648 MOTOROLAHIPERCOMM BR1334 Rev 4 6 Typical transfer characteristics for the oscillator in the voltage controlled mode are shown in Figure 6, Figure 7 and Figure 8. Figure 6 and Figure 8 show transfer characteristics employing only the capacitance of the varactor diode (p

30、lus the input capacitance of the oscillator, 6.0pF typical). Figure 7 illustrates the oscillator operating in a voltage controlled mode with the output frequency range limited. This is achieved by adding a capacitor in parallel with the tank circuit as shown. The 1.0k resistor in Figure 6 and Figure

31、 7 is used to protect the varactor diode during testing. It is not necessary as long as the dc input voltage does not cause the diode to become forward biased. The largervalued resistor (51k) in Figure 8 is required to provide isolation for the highimpedance junctions of the two varactor diodes. The

32、 tuning range of the oscillator in the voltage controlled mode may be calculated as: fmax fmin ? CD(max) ? CS ? CD(min) ? CS ? wherefmin? 1 2?L(CD(max) ? CS) ? CS = shunt capacitance (input plus external capacitance) CD = varactor capacitance as a function of bias voltage Good RF and lowfrequency by

33、passing is necessary on the power supply pins. (See Figure 2) Capacitors (C1 and C2 of Figure 4) should be used to bypass the AGC point and the VCO input (varactor diode), guaranteeing only dc levels at these points. For output frequency operation between 1.0MHz and 50MHz a 0.1F capacitor is suffici

34、ent for C1 and C2. At higher frequencies, smaller values of capacitance should be used; at lower frequencies, larger values of capacitance. At high frequencies the value of bypass capacitors depends directly upon the physical layout of the system. All bypassing should be as close to the package pins

35、 as possible to minimize unwanted lead inductance. The peaktopeak swing of the tank circuit is set internally by the AGC circuitry. Since voltage swing of the tank circuit provides the drive for the output buffer, the AGC potential directly affects the output waveform. If it is desired to have a sin

36、e wave at the output of the MC1648, a series resistor is tied from the AGC point to the most negative power potential (ground if +5.0 volt supply is used, 5.2 volts if a negative supply is used) as shown in Figure 10. At frequencies above 100 MHz typ, it may be desirable to increase the tank circuit

37、 peaktopeak voltage in order to shape the signal at the output of the MC1648. This is accomplished by tying a series resistor (1.0k minimum) from the AGC to the most positive power potential (+5.0 volts if a +5.0 volt supply is used, ground if a 5.2 volt supply is used). Figure 11 illustrates this p

38、rinciple. APPLICATIONS INFORMATION The phase locked loop shown in Figure 9 illustrates the use of the MC1648 as a voltage controlled oscillator. The figure illustrates a frequency synthesizer useful in tuners for FM broadcast, general aviation, maritime and landmobile communications, amateur and CB

39、receivers. The system operates from a single +5.0Vdc supply, and requires no internal translations, since all components are compatible. Frequency generation of this type offers the advantages of single crystal operation, simple channel selection, and elimination of special circuitry to prevent harm

40、onic lockup. Additional features include dc digital switching (preferable over RF switching with a multiple crystal system), and a broad range of tuning (up to 150MHz, the range being set by the varactor diode). The output frequency of the synthesizer loop is determined by the reference frequency an

41、d the number programmed at the programmable counter; fout = Nfref. The channel spacing is equal to frequency (fref). For additional information on applications and designs for phase lockedloops and digital frequency synthesizers, see Motorola Brochure BR504/D, Electronic Tuning Address Systems, (ETA

42、S). Figure 10 shows the MC1648 in the variable frequency mode operating from a +5.0Vdc supply. To obtain a sine wave at the output, a resistor is added from the AGC circuit (pin 5) to VEE. Figure 11 shows the MC1648 in the variable frequency mode operating from a +5.0Vdc supply. To extend the useful

43、 range of the device (maintain a square wave output above 175Mhz), a resistor is added to the AGC circuit at pin 5 (1.0 kohm minimum). Figure 12 shows the MC1648 operating from +5.0Vdc and +9.0Vdc power supplies. This permits a higher voltage swing and higher output power than is possible from the M

44、ECL output (pin 3). Plots of output power versus total collector load resistance at pin 1 are given in Figure 13 and Figure 14 for 100MHz and 10MHz operation. The total collector load includes R in parallel with Rp of L1 and C1 at resonance. The optimum value for R at 100MHz is approximately 850 ohm

45、s. MC1648 HIPERCOMM BR1334 Rev 4 7MOTOROLA Figure 9. Typical Frequency Synthesizer Application Phase Detector MC4044 fref Counter Control Logic MC12014 MC12012 P, (P+1) Np Programmable Counter MC4016 A Programmable Counter MC4016 Low Pass Filter Voltage Controlled Oscillator MC1648 Modulus Enable Li

46、ne Zero Detect Line fout N = Np P + A Counter Reset Line fout fout = Nfref where N = Np P + A Figure 10. Method of Obtaining a SineWave OutputFigure 11. Method of Extending the Useful Range of the MC1648 (Square Wave Output) 10 12 78 3 5 Output +5.0Vdc 10 12 78 3 5 Output +5.0Vdc 114114 1.0k min MC1

47、648 MOTOROLAHIPERCOMM BR1334 Rev 4 8 Figure 12. Circuit Used for Collector Output Operation 10 12 0.1F 3 5 Bias Point L2*Tank C2 1.0F VCC2141VCC1 C1 L1 +5.0V C3 R 0.01F +9.0V AGC +5.0V 1.0F 1.2k 8VEE27VEE1 * QL 100 Output Figure 13. Power Output versus Collector LoadFigure 14. Power Output versus Co

48、llector Load TOTAL COLLECTOR LOAD (OHMS) 7 10 TOTAL COLLECTOR LOAD (OHMS) POWER OUTPUT (mW RMS) 0 10,000 6 5 4 3 2 1 1001000 POWER OUTPUT (mW RMS) 1010,0001001000 14 0 12 10 8 6 4 2 See test circuit, Figure 12, f = 100MHz C3 = 3.035pF Collector Tank L1 = 0.22HC1 = 1.07.0pF R = 5010k RP of L1 and C1

49、= 11k 100MHz Resonance Oscillator Tank L2 = 4 turns #20 AWG 3/16” ID C2 = 1.07.0pF See test circuit, Figure 12, f = 10MHz C3 = 470pF Collector Tank L1 = 2.7HC1 = 24200pF R = 5010k RP of L1 and C1 = 6.8k 10MHz Resonance Oscillator Tank L2 = 2.7H C2 = 16150pF MC1648 HIPERCOMM BR1334 Rev 4 9MOTOROLA OUTLINE DIMENSIONS P SUFFIX PLASTIC PACKAGE CASE 64606 ISSUE L 18.16 6.10 3.69 0.38 1.02 1.32 0.20 2.92 0 0.39 19.56 6.60 4.69 0.53 1.78 2.41 0.38 3.43 10 1.01 2.54 BSC 7.62 BSC 0.715 0.240 0.