3. TECHNICAL BRIEF
- 18 -
Figure 3-4 SI4205 FREQUENCY SYNTHESIZER PART
The Aero I transceiver integrates two complete PLLs including VCOs, varactors, resonators, loop
filters, reference and VCO dividers, and phase detectors. The RF PLL uses two multiplexed VCOs.
The RF1 VCO is used for receive mode, and the RF2 VCO is used for transmit mode. The IF PLL
is used only during transmit mode. All VCO tuning inductors are also integrated. The IF and RF out-
put frequencies are set by programming the N-Divider registers, NRF1, NRF2and NIF.
Programming the N-Divider register for either RF1 or RF2 automatically selects theproper VCO.
The output frequency of each PLL is as follows:
The DIV2 bit in register 31h controls a programmable divider at the XIN pin to allow either a 13 or
26 MHz reference frequency. For receive mode, the RF1 PLL phase detector update rate (ƒ
ø
)
should be programmed ƒ
ø
= 100 kHz for DCS 1800 or PCS 1900 bands, and ƒ
ø
= 200 kHz for GSM
850 and E-GSM 900 bands. For transmit mode, the RF2 and IF PLL phase detector update rates
are always ƒ
ø
=200 kHz.
(3) Frequency Synthesizer
Summary of Contents for B2050
Page 7: ... 6 2 PERFORMANCE 2 PERFORMANCE 2 1 H W Features ...
Page 8: ... 7 2 PERFORMANCE ...
Page 9: ... 8 2 PERFORMANCE 2 2 Technical Specification ...
Page 10: ... 9 2 PERFORMANCE ...
Page 11: ... 10 2 PERFORMANCE ...
Page 12: ... 11 2 PERFORMANCE ...
Page 13: ... 12 2 PERFORMANCE ...
Page 57: ... 56 3 Checking Ant SW Mobile SW 4 TROUBLE SHOOTING ...
Page 67: ... 66 TEST POINT 4 6 LCD Trouble 4 TROUBLE SHOOTING ...
Page 70: ... 69 4 TROUBLE SHOOTING TEST POINT 4 7 Speaker Trouble ...
Page 77: ... 76 4 TROUBLE SHOOTING 4 10 KEY backlight Trouble TEST POINT ...
Page 92: ...5 DOWNLOAD AND CALIBRATION 91 5 2 Calibration ...
Page 93: ... 92 5 DOWNLOAD AND CALIBRATION ...
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Page 103: ... 102 Figure 8 1 B2050 BOTTOM SIDE PCB LAYOUT 8 PCB LAYOUT ...
Page 104: ... 103 8 PCB LAYOUT Figure 8 1 B2050 TOP SIDE PCB LAYOUT ...
Page 105: ......
Page 113: ...10 STAND ALONE TEST 112 ...
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Page 133: ... 132 ...