Shure_SLX2_Wireless_Mic_Service_Manual 电路图.pdf

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1、SLX2 Wireless Transmitter Service Manual 2006, Shure Incorporated 25A1090 (Rev.3) 25A1090 SLX2 WIRELESS HANDHELD TRANSMITTER PRODUCT DESCRIPTION The Shure Model SLX2 is a P (microprocessor) controlled frequency agile UHF handheld transmitter operating over the frequency range of 518 to 865 MHz (in e

2、ight different 24 MHz-wide frequency bands). The transmitter will operate for a minimum of 8 hours using two AA alkaline batteries. The User Interface includes mode and set buttons, and an LCD that displays battery status, group/channel, and transmitter/ receiver frequency synchronization. The SLX2

3、has a plastic enclosure, and utilizes an internal antenna for optimum range and reliability. This product is intended for use in entry-level presentation, installed, and performance markets. FEATURES 1.Frequency agile; microprocessor controlled. Model number extension determines frequency band of op

4、eration. 2.Minimum of 12 compatible systems per SKU in the U.S. Additionally, a minimum of 12 compatible systems in the top 50 U.S. markets across all three domestic SKUs (H5, J3, and L4). 3.Operating frequency programmable locally or from the receiver using a built-in IR link. 4.Designed for use wi

5、th AA alkaline batteries (2 required). May also be used with rechargeable AA batteries. Note: battery condition indicator is calibrated for alkaline batteries and may not be accu- rate with rechargeable types. Electrical reverse battery protection is included. 5.Minimum battery life of 8 hours with

6、new AA alkaline batteries. 6.Designed for use with SM58, BETA 58, SM86, and BETA 87A therefore, if the tone key or the transmitter is turned off, the receiver will be muted. The tone key squelch will eliminate receiver noise associated with loss of the carrier, which usually sounds like a pop. The t

7、one key signal is generated by a square wave from the mP (IC300). It is then filtered by active filter stage Q185 and attenuated by R188/R189 (under P control) before being fed to the summing amplifier. The combined audio/tone-key signal is then sent to the VCO through R504. POWER SECTION Two AA bat

8、teries supply power to the transmitter through FET Q410, which provides electri- cal reverse battery protection. Next, power enters switching boost converter IC400, which sup- plies regulated 5V power. To turn on the transmitter, SW325 shorts the base of Q480 to ground, enabling the converter and po

9、wering up the unit. The microprocessor keeps Q480 disabled until shutdown. Power is turned off by a shutdown signal from the microprocessor, which can be initiated manually by the user (by holding down SW325 for 2.2 seconds) or automatically by the system (e.g., when the battery is too weak for prop

10、er operation). At this time, the microprocessor enables Q480 and shuts down the converter. When the unit is off, Q480 and its bias circuitry draw less than 30 A, so the effect on battery life is negligible. The converter and microprocessor are dis- abled. LOW BATTERY SHUT DOWN: A software battery sh

11、utdown routine allows the battery supply to run down to 2.05 V before shutdown, and will not turn the system back on until a voltage greater than 2.25 V is present. The hysteresis keeps the system in a controlled state when the batteries are low, and also helps pre- vent weak batteries from being us

12、ed from the start. RF CIRCUIT DESCRIPTION RF SECTION The system block diagram is shown above. The SLX2 uses a PLL system with direct carrier frequency modulation. Processed audio enters the VCO through a passive reflection network before being applied to the varactor diode (D500) through choke L503.

13、 The VCO is shielded to prevent external RF fields from affecting its operation, and to help control radiated emissions of its harmonics. Power for the VCO and PLL circuitry is supplied by the main 5 V regulator. Power and signal lines in the VCO area are heavily decoupled and bypassed to remove noi

14、se. The VCO has a tuning bandwidth of more than 30 MHz on all bands, with a tuning voltage range of approximately 1 to 4 volts. The VCO employs separate stages for the oscillator (Q502) and buffer (Q501) to minimize phase noise and load pulling. The VCO output is isolated by ca- pacitive and resisti

15、ve dividers, before being applied to the frequency control pin of the PLL syn- thesizer (IC501) through C538. The synthesizers internal circuitry divides the RF signal down as necessary to achieve a tuning precision of 25 kHz. The synthesizer circuit contains a quartz-con- trolled reference oscillat

16、or operating from a 16 MHz reference crystal (Y801) that is adjusted by means of trimmer CV501. The transmitter output frequency is user selectable in groups of com- patible channels within each of the eight available bands. Frequency selection is made via mi- croprocessor controller IC300, which in

17、terfaces with the user by means of the Group and Channel switches, SW324 and SW325. The output of the synthesizer is a series of pulses that are integrated by a passive loop filter consisting of C532, R514, C533, R513, and C531 to pro- duce the control voltage signal. The VCO output is coupled to th

18、e RF buffer stage (Q600) by a matching network consisting of R602, C614, and L610. R600 and R603 provide base bias for the transistor, while R605 sets its operating current. RF choke L600 provides power and decoupling for the stage, in conjunction 6 25A1090 (Rev.3) with C600 - C604. The collector of

19、 Q600 feeds the power amplifier stage via an impedance matching network consisting of L602, C611, and C618. The bias voltage for the RF power amplifier (Q601) is supplied by R601 and R604. Its operat- ing current is controlled via emitter resistor R606. RF choke L601 provides power and decoupling fo

20、r the stage, in conjunction with C605-C609. For Japanese systems only, the output power is trimmed via TR640. L603, C612, and L604 provide the output impedance matching into the low pass filter, which consists of L604, L605, L606, C615, C616, and C617. The low pass filter output couples to the batte

21、ry antenna via C641 and L607. Connector CON640 and C613 are only used for Japanese (JB) units. Coupling capacitor C610 is used to ensure that both batteries are driven equally. The transmitter is capable of delivering up to +15.0 dBm to the antenna (depending on band and country). During transmitter

22、 power-up and frequency selection, the RF output is muted by bringing the base of Q631 low, which removes bias from Q630 and shuts down power to the RF stages. The RF output is also muted during the transmitter power-down sequence. This is done so that the carrier signal will not interfere with othe

23、r transmissions when the loop becomes unlocked. DIGITAL CIRCUIT DIAGRAM RF Band DC Level Battery DC Level Power Mute Button Select Button Softstart Shutdown Infrared Photodetector (Sharp GP1U10X) EEPROM (MicroChip 93AA46 ) Microprocessor (Motorola MC68HC908GR16) Backlight LED Power LED LCD VCO RF Po

24、wer Tonekey Squarewave Tonekey Level LCD Driver (Rohm BU9729k) Sythesizer (National Semiconducter LMX2335) Audio Mute 7 25A1090 (Rev.3) DIGITAL SECTION ACCESSING DIFFERENT MODES ATE MODE If TP_PB0 is held to TP_EGND, or logic level 0, at startup, the microcontroller will enter ATE Mode. To ensure pr

25、oper operation, TP_PA0 and TP_PA1 should be held to TP_EGND at startup. In ATE Mode, each band has a three test frequencies that are controlled by the logic levels at test points TP_PA0 and TP_PA1. RF BAND RESISTORS Two resistors (RA and RB) are responsible to start the microcontroller in a RF band.

26、 They de- termine the voltage at test point TP_RFBAND. This table shows RAs and RBs reference designators and how the voltages at the test points reflect the operating RF band. This figure depicts the voltage divider feeding the microprocessor analog to digital converter. . FrequencyTP_PA0 TP_PA1 Lo

27、w00 Center01 High11 Test Frequencies (MHz)H5J3JBL4P4Q4R5S6 SLX2Low518.400572.400806.125638.400702.100740.125800.525838.100 Center529.500583.500807.500649.500714.000746.325810.275851.300 High541.800595.800809.750661.800725.900751.875819.800864.800 SLX Reference Designators SLX2 RARB R319R320 8 25A109

28、0 (Rev.3) This table shows the variant resistor values and resulting voltages at TP_RFBAND for each band. Note: Voltages are calculated with a 3.30V (+/- 0.10V) reference from the power supplies. If power section supports less than 3.30V, thresholds need to be adjusted. C DECISIONS BASED ON ANALOG V

29、OLTAGES Note: There is a dead battery lock voltage set at 2.30 Volts. If the transmitter is powered on with a voltage of less than 2.30 Volts, the system will lock, forcing the user to either recharge or replace the batteries. During the dead battery lock out, the battery gauge is empty and the red

30、led flashes. RF BANDRb TP_RFBAND(+/- 0.10V) H51.00k0.30V J32.99k0.76V L44.99k1.10V R57.50k1.41V S612.10k1.81V P418.2k2.13V Q430.1k2.48V JB49.9k2.75V Continuous Operation Battery Thresholds BATTERY_A2DRF LevelDisplayLogicVoltage (V) Measured 3V block battery clips - dBC=2.25 - dBC2.25 - dBC2.14 -8 dB

31、C 120 Group 1Group 2Group 3Group 4Group 5Group 6 1518.400519.250518.200519.775519.100518.425 2521.500520.500519.675522.500521.225520.400 3523.575522.225520.800524.200522.550523.425 4525.050524.725522.450525.600524.575525.475 5527.425526.350523.750526.700526.900527.775 6529.200527.550526.200528.25053

32、0.500531.675 7532.450530.800528.325529.500531.750533.800 8533.650532.575532.225533.100533.300536.250 9535.275534.950534.525535.425534.400537.550 10537.775536.425536.575537.450535.800539.200 11539.500538.500539.600538.775537.500540.325 12540.750541.600541.575540.900540.225541.800 Explanation of group

33、 content Full Range even distribution for each TV-CH (option 1) Full Range even distribution for each TV-CH (option 2) Full Range max. # of frequencies for CH- 22 (option 1) Full Range max. # of frequencies for CH- 23 (option 1) Full Range max. # of frequencies for CH- 24 (option 1) Full Range max.

34、# of frequencies for CH- 25 (option 1) Preprogrammed frequencies in total: 120 Group 1Group 2Group 3Group 4Group 5Group 6 1572.400573.250572.200573.775573.100572.425 2575.500574.500573.675576.500575.225574.400 3577.575576.225574.800578.200576.550577.425 4579.050578.725576.450579.600578.575579.475 55

35、81.425580.350577.750580.700580.900581.775 6583.200581.550580.200582.250584.500585.675 7586.450584.800582.325583.500585.750587.800 8587.650586.575586.225587.100587.300590.250 9589.275588.950588.525589.425588.400591.550 10591.775590.425590.575591.450589.800593.200 11593.500592.500593.600592.775591.500

36、594.325 12594.750595.600595.575594.900594.225595.800 Explanation of group content Full Range even distrobution for each TV-CH (option 1) Full Range even distrobution for each TV-CH (option 2) Full Range max. # of frequencies for CH- 31 (option 1) Full Range max. # of frequencies for CH- 32 (option 1

37、) Full Range max. # of frequencies for CH- 33 (option 1) Full Range max. # of frequencies for CH- 34 (option 1) 19 25A1090 (Rev.3) JB: 806.000 - 810.000 MHZ L4: 638.000 - 662.000 MHZ Preprogrammed frequencies in total: 21 Group 1Group 2Group 3Group 4Group 5Group 6 1806.250806.375806.125806.500806.12

38、5806.250 2807.500808.625807.375807.375807.375807.250 3809.625809.750809.500808.625808.375808.500 4809.625809.750809.375 Explanation of group content Full Range max. # of compatible frequencies (option 1) Full Range max. # of compatible frequencies (option 2) Full Range max. # of compatible frequenci

39、es (option 3) Full Range max. # of compatible frequencies (option 4) Full Range max. # of compatible frequencies (option 5) Full Range max. # of compatible frequencies (option 6) Preprogrammed frequencies in total: 120 Group 1Group 2Group 3Group 4Group 5Group 6 1638.400639.250638.200639.775639.10063

40、8.425 2641.500640.500639.675642.500641.225640.400 3643.575642.225640.800644.200642.550643.425 4645.050644.725642.450645.600644.575645.475 5647.425646.350643.750646.700646.900647.775 6649.200647.550646.200648.250650.500651.675 7652.450650.800648.325649.500651.750653.800 8653.650652.575652.225653.1006

41、53.300656.250 9655.275654.950654.525655.425654.400657.550 10657.775656.425656.575657.450655.800659.200 11659.500658.500659.600658.775657.500660.325 12660.750661.600661.575660.900660.225661.800 Explanation of group content Full Range even distribution for each TV-CH (option 1) Full Range even distrib

42、ution for each TV-CH (option 2) Full Range max. # of frequencies for CH- 42 (option 1) Full Range max. # of frequencies for CH- 43 (option 1) Full Range max. # of frequencies for CH- 44 (option 1) Full Range max. # of frequencies for CH- 45 (option 1) 20 25A1090 (Rev.3) P4: 702.000 - 726.000 MHZ P4:

43、 702.000 - 726.000 MHZ CONTINUED Preprogrammed frequencies in total: 148 1212121010991011 Group 1Group 2Group 3Group 4Group 5Group 6Group 7Group 8Group 9 1702.200703.750703.650702.750703.750702.100704.775702.300703.000 2704.200705.975705.650704.500705.750704.025706.225704.975706.025 3707.200707.2007

44、08.650705.750708.250705.500710.500706.775708.000 4709.425708.850710.875708.250711.750708.500712.025709.100710.300 5711.000710.950712.450711.250714.500710.100714.225710.300712.225 6713.675712.425715.125712.500715.750712.025716.900712.225716.000 7715.575714.325717.025715.250718.750713.500718.500714.77

45、5717.100 8717.050717.000718.500718.750721.250717.300720.775716.700719.000 9719.150718.575720.600721.250722.500725.300725.300724.000720.225 10720.800720.800722.250723.250724.250 725.900722.775 11722.025723.800723.475 724.700 12724.250725.800725.700 Explanation of group content Full Range max. # of co

46、mpatible frequencies (option 1) Full Range max. # of compatible freque-cies (option 2) Full Range max. # of compatible frequencies (option 3) France preferred: User Group A (option 1) France preferred: User Group A (option 2) France preferred: User Group B (option 1) France preferred: User Group B (

47、option 2) France preferred: User Group C (option 1) France preferred: User Group C (option 2) 665108108 Group 10Group 11Group 12Group 13Group 14Group 15Group 16 1702.200710.200718.200702.550702.100702.700702.500 2703.300711.300719.300705.600704.700704.700705.500 3704.700712.700720.700707.500710.3007

48、09.450707.000 4705.800713.800721.800709.000712.400711.500712.200 5707.675715.675723.675711.500714.000714.500714.100 6708.775716.775 715.100716.500716.550716.400 7 717.000719.400719.900719.500 8 720.000721.300722.000722.200 9 723.500 724.700 10 725.900 725.900 11 12 Explanation of group content Optim

49、ized TV channels: TV ch. 50 702-710 MHz Optimized TV channels: TV ch. 51 710-718 MHz Optimized TV channels: TV ch. 52 718-724 MHz Compatible setup for use with PSM400-P3 (P4 P3) Compatible setup for use with PSM400-P3 (P4 = P3) Compatible setup for use with PSM400-HF (P4 HF) Compatible setup for use with PSM400-HF (P4 = HF) 21 25A1090 (Rev.3) Q4: 740.000 - 752.000 MHZ Preprogrammed frequencies in total: 36 Group 1Group 2Group 3Group 4 1740.125740.12574