- 您現(xiàn)在的位置：買賣IC網 > PDF目錄300104 > WE904 (Electronic Theatre Controls, Inc.) 0.1 - 1GHx Single Chip FM Transceiver PDF資料下載
參數資料
| 型號： | WE904 |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | 0.1 - 1GHx Single Chip FM Transceiver |
| 中文描述： | 0.1 - 1GHx單芯片F(xiàn)M收發(fā)器 |
| 文件頁數： | 8/39頁 |
| 文件大小： | 623K |
| 代理商： | WE904 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁當前第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁
Winceiver WE904/WE905
WiNEDGE & WiRELESS
0.1 - 1GHz Single Chip FM Transceiver
2003 WiNEDGE & WiRELESS PTE LTD
Page 16
Rev Date: 2003 May 27
RECEIVER BANDWIDTH ADJUSTMENT
The application circuit diagram is given for a 915MHz ISM band receiver with a 130kHz bandwidth.
The Rx bandwidths can be adjusted from 16kHz to 150kHz. Some of the bandwidth setting
adjustments scale with the RF frequency. There are 3 major elements related to the receiver
bandwidth:
Baseband Bandwidth
BWbb: the baseband bandwidth. This is defined by 8 pole low pass filters in both the I and Q
baseband channels. The filtering in each channel is achieved by a two pole Sallen Key filter
combined with a six pole Gm filter. The defining resistors and capacitors for the Sallen Key
filters are off chip; the Gm filter is totally on-chip except for one bandwidth trimming resistor.
Note that the bandwidth of the individual baseband I and Q channels is half of the
demodulator bandwidth. For example, a receiver working at 915MHz with a bandwidth of
130kHz (i.e.
65kHz), baseband bandwidth BWbb is 65kHz, demodulator bandwidth BWdm
is 130kHz minimum.
The DC offset correction feedback loop in the baseband section introduces an effective high
pass filter (100Hz) in the center of the RF band.
Demodulator Bandwidth
BWdm: the demodulator bandwidth. This is the bandwidth of the Period to Digital
demodulator. It is a ‘brick wall’ filter centered on the IF frequency. BWdm must be wider than
receive bandwidth.
IF Bandwidth
There is filtering in the IF section following the second mixer, designed to attenuate mixer
products prior to the demodulator. Filtering is defined by a 4 pole low pass filter followed by a
single pole high pass filter. The low pass filter is an on-chip Gm design with an off-chip
bandwidth trimming resistor and the high pass filter is on-chip and fixed frequency at 8kHz.
The following sections shows how the bandwidth of these sections can be adjusted.
BASEBAND FILTERS BANDWIDTH
A. Sallen Key baseband filters
The R and C components for this filter are off chip. To set the baseband bandwidth, BWbb, adjust the
C values. Choose values to give a bandwidth equal to or slightly greater than the required bandwidth
according to the following formulae.
The recommended component tolerances for resistors should be 1%, with capacitor tolerances of
5%, or better.
Capacitor attached to IFIL2/QFIL2 = 1.8nF x (65kHz/BWbb)
Capacitor attached to IFIL3/QFIL3 = 0.68nF x (65kHz/BWbb)
E.G.,
for a required 32kHz bandwidth, BWbb=16kHz, suggested values of 6.8nF and 2.6nF give a
bandwidth of 34kHz.
相關PDF資料 |
PDF描述 |
|---|---|
| WE905 | 0.1 - 1GHx Single Chip FM Transceiver |
| WED2DG472512V65D2 | 2M X 72 MULTI DEVICE SRAM MODULE, 3.7 ns, DMA168 |
| WED3DG64128V10D1 | 128M X 64 SYNCHRONOUS DRAM MODULE, DMA144 |
| WED3DG64128V75D1 | 128M X 64 SYNCHRONOUS DRAM MODULE, DMA144 |
| WED3EG6417S262D4 | 16M X 64 DDR DRAM MODULE, DMA200 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| WE905 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:0.1 - 1GHx Single Chip FM Transceiver |
| WE9104 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Pulse Telephone Dialer |
| WE9110 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Pulse Telephone Dialer |
| WE9140 | 制造商:WINBOND 制造商全稱:Winbond 功能描述:TONE/PULSE SWITCHABLE DIALER WITH REDIAL |
| WE9140A | 制造商:WINBOND 制造商全稱:Winbond 功能描述:TONE/PULSE SWITCHABLE DIALER WITH REDIAL |
發(fā)布緊急采購，3分鐘左右您將得到回復。