Motorola Gp328 Gp338 Detailed 6804110j64 F Manual
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Frequency Generation Circuitry6A-95.0 Frequency Generation CircuitryThe Frequency Generation Circuitry is composed of two main ICs, the Fractional-N synthesizer (U201), and the VCO/Buffer IC (U241). Designed in conjunction to maximize compatibility, the two ICs provide many of the functions that normally would require additional circuitry. The synthesizer block diagram illustrates the interconnect and support circuitry used in the region. Refer to the relevant schematics for the reference designators....
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6A-10Frequency Generation Circuitry5.1 Synthesizer(Refer toUHF Synthesizer Schematic Diagramon page 6A-20) The Fractional-N Synthesizer uses a 16.8MHz crystal (FL201) to provide a reference for the system. The LVFractN IC (U201) further divides this to 2.1MHz, 2.225MHz, and 2.4MHz as reference frequencies. Together with C206, C207, C208, R204 and CR203 , they build up the reference oscillator which is capable of 2.5ppm stability over temperatures of -30 to 85°C. It also provides 16.8MHz at pin 19 of U201...
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Frequency Generation Circuitry6A-115.2 VCO - Voltage Controlled Oscillator(Refer toUHF Voltage Controlled Oscillator Schematic Diagramon page 6A-21) Figure 6-5VCO Block Diagram The VCOBIC (U241) in conjunction with the Fractional-N synthesizer (U201) generates RF in both the receive and the transmit modes of operation. The TRB line (U241 pin 19) determines which oscillator and buffer will be enabled. A sample of the RF signal from the enabled oscillator is routed from U241 pin 12, through a low pass...
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6A-12Frequency Generation CircuitryThe VCOBIC(U241) is operated at 4.54 V (VSF) and Fractional-N synthesizer (U201) at 3.3V. This difference in operating voltage requires a level shifter consisting of Q260 and Q261 on the TRB line. The operation logic is shown in Table 6-1. In the receive mode, U241 pin 19 is low or grounded. This activates the receive VCO by enabling the receive oscillator and the receive buffer of U241. The RF signal at U241 pin 8 is run through a matching network. The resulting RF...
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Notes For All Schematics and Circuit Boards 6A-136.0 Notes For All Schematics and Circuit Boards* Component is frequency sensitive. Refer to the Electrical Parts List for value and usage. 1.Unless otherwise stated, resistances are in Ohms (k = 1000), and capacitances are in picofarads (pF) or microfarads (µF). 2.DC voltages are measured from point indicated to chassis ground using a Motorola DC multime- ter or equivalent. Transmitter measurements should be made with a 1.2 µH choke in series with the...
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6A-14 Notes For All Schematics and Circuit Boards
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Circuit Board/Schematic Diagrams and Parts List 6A -15 7.0 Circuit Board/Schematic Diagrams and Parts List L400R421 TP405 VR434 VR450 CR413Q417 3 4 TP406 J403 20 22C441 C491 C492C490 C493 C494 C495 C496C497 R477 R450 21 1C471 C472 C473 L401 TP410 VR447 VR449 C443 40 R435 TP401 TP402C427 C444C428 RT400 85 4 1U407 J400 C423 E407 E408 E409 R418R437R410 SH400 821 U405 1 7 22 C426 C425 C429 C424 R408 R492R429 R478 R428 1 16 U406 17 32PB503 3 FL201 B503 C432 SH201TP201 C220 C229 C217 C228 L201 L203 C260 C294...
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6A -16Circuit Board/Schematic Diagrams and Parts List C108 J101 4 3 2 J102 R1012 S501 C 8 C 4 CR303L303 SH302 C307 R340 R328 C309 R303R304 C315C321 C310 C314C306 C311 R347 R305 C313C318 C380 C316 C317C312 CR304 CR305 R306 R307C395 L340 L306 L307 L305 L304Q301 C337 C347 C348 C356C339 C340 C341 C342 C343 C383 C390 C346 C357C358 R344 C345 C334 C359 SH322 13 25 37 1U301 C329 C336 C360 C355C361 L314C344C382 L331 R343 R350 C327C330 C326 C338L330 Q302 R315R313R311 R312 C503 CR306 F501 SH304 C123 E101 R329...
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Circuit Board/Schematic Diagrams and Parts List 6A -17 DEMOD LVZIF_SEL RSSI 16.8MHzCLK DACRx DATA Vdda Vdda RX_IN RX_INJR5 RECEIVER DATA CLK DACRX DEMOD RSSI LVZIF_SEL 16.8MHz RX_INJSWB+ TX_INJ Vdda FGU 16.8MHz 4V_3.3V 5V CLK CSX DATA LOCK MODIN R5 CSX 4V_3.3VSWB+ LOCK MODIN 5V DATA RESET RX_IN TX_INJ UNSWB+ TRANSMITTER 5V CLK CSX 5V UNSWB+ RESETB503 B504 LI_ION C505 100pFR507 0 C502 0.47uF VR5016.8V1 5 HIGH32SWITCH S502 4 LOW Vdda VOLMECH_SWB+ 100pFC503VR506 6.8V 10V VR439L505 390nH 24V 2 1F501 2CR501...
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6A -18Circuit Board/Schematic Diagrams and Parts List 100pF C386 Q310 13 2NU R331C372 R330 C371 NU NUNUNU 21R335 RT301 R338 C391 6.8K R325 R5 NUNU NU NU VR300 R326Q3161 3 2 R334NU NU NUNU33.0KRT300 2 1 1 3 2Q315 R319 150R318 18K R327 33K C333 R336 R5 NU NUR316 91K C396 NU C397 1uF2.2K R300 RSSI RX_INJ 100pFC3700 R339 R332 NU100pFC374 R333 0 R349 L321 C373 NU NU NUC378 NU 100pFC375 16.28nHL309 C320 C319 7.5pF 1.8pF2 T302 XFMR 4 63 1 C381 9.1pF TP302 3.6K R348 R5 7.5pFC318 9.1pFC317R329 0 CR305 CR304100K...