- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄358961 > LV2700V (Sanyo Electric Co.,Ltd.) Spread Spectrum Communications IC(頻譜擴展通訊芯片) PDF資料下載
參數(shù)資料
| 型號： | LV2700V |
| 廠商： | Sanyo Electric Co.,Ltd. |
| 英文描述： | Spread Spectrum Communications IC(頻譜擴展通訊芯片) |
| 中文描述： | 擴頻通信集成電路（頻譜擴展通訊芯片） |
| 文件頁數(shù)： | 13/20頁 |
| 文件大?。?/td> | 343K |
| 代理商： | LV2700V |
FM Demodulation
The PN code of the reference phase described above is used in the unspreading unit for the signals. Further, the PLL in
the last stage of the unspreading unit carries out the operation of not only the above PN synchronization maintenance
but also functions as an FM demodulator so that the data signal is obtained at the end of the loop filter. However, since
it is not possible to set the loop bandwidth to be sufficiently narrow because of the setting of the initial acquisition time
response characteristics, the PN component cannot be sufficiently suppressed at the end of the loop filter. Therefore, a
150kHz LPF is provided at the demodulator output thereby removing the leakage components of the PN code thus
improving the S/N ratio. If the S/N ratio is to be further improved by limiting the demodulation bandwidth, it is
necessary to add another LPF.
Application Information
1. Operating Mode Selection
The selection of the transmission mode and the reception mode is set as follows by the input at pin 15 and the method
of applying the voltage at the power supply terminal. Note that the power supply to the bias circuit of the circuit
block dedicated to the RX mode is automatically made OFF by pin 15 during the TX mode thereby saving power
dissipation.
2. RF Block
Since the LV2700V carries out direct signal processing at 236 MHz without converting to an IF frequency, it is
possible to configure a transmitting and receiving system with a minimum of external components. The standard
operating frequency of 236 MHz has been selected so that it can be used as such in systems using weak radio waves.
In addition, by combining with an up-converter or a down-converter so that the IF frequency becomes 236 MHz, it is
possible to use this IC even in ISM bands such as 2.4 GHz, etc.
The LV2700V has a 15 dB RF amplifier in the input block, and hence is it possible to obtain an input sensitivity of
about –100dBm by using an external RF amplifier of about 25 dB. Further, it is necessary to place a BPF in the latter
stage of the antenna thereby removing components outside the band of interest and thus improving the interference
characteristics and the input sensitivity.
3. VCO
TX Mode
The VCO output is adjusted by the PLL circuit to a frequency that is 24 times the reference oscillator frequency, that is,
236 MHz. The reference oscillator circuit is configured by an inverter using a quartz oscillator element of 9.8304 MHz.
Also, the phase comparator uses an EX-OR gate and carries out the comparison operation at the reference frequency.
Further, since the clock of the PN code generator is generated by frequency division of the VCO output by 24, its
frequency becomes equal to the reference frequency.
RX Mode
In the reception mode, the input signal will be the reference signal for the PLL. Therefore, under the no-signal
condition, the VCO will be in the free running state. The phase comparator carries out phase comparison at 236 MHz
using an analog mixer circuit. By using a circuit configuration in which there is no frequency divider between the
VCO and the phase comparator, the PLL loop gain is made large thereby increasing the input sensitivity of the PLL
itself. The PN clock is generated by frequency dividing the VCO output by 24 similar to that in the transmission mode.
No. 5651-13/20
LV2700V
Mode
Pin 15
Power supply terminal setting method
TX
High
Voltages are applied to all the power supply terminals.
RX
Low
The voltage is applied to all power supply terminals except pin 27.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LV3100M | Parametric Equalizer |
| LV320MH | 32 Megabit (4 M x 8-Bit) MirrorBit⑩ 3.0 Volt-only Uniform Sector Flash Memory with VersatileI/O⑩ Control |
| LV3400M | FM Multiplex Filter(FM多路濾波器) |
| LV3400 | FM Multiplex Filter |
| LV3403M | 3V Operation Filter for FM Multiplex Broadcasting Reception(用于FM多路廣播接收的3V運算濾波器) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LV-271M2G---3035S | 制造商:Surge Components Inc 功能描述:CAP ALUM 270UF 400V ?20% 2000LHRS 30 X 35 - Bulk |
| LV-271M2W---2550S | 制造商:Surge Components Inc 功能描述:CAP ALUM 270UF 450V ?20% 2000LHRS 25 X 50 - Bulk |
| LV-271M2W---3040S | 制造商:Surge Components Inc 功能描述:CAP ALUM 270UF 450V ?20% 2000LHRS 30 X 40 - Bulk |
| LV-271M2W---3535S | 制造商:Surge Components Inc 功能描述:CAP ALUM 270UF 450V ?20% 2000LHRS 35 X 35 - Bulk |
| LV275DI-Q4 | 制造商:Okaya Electric America Inc 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。