參數(shù)資料
型號： ZL20250
廠商： Zarlink Semiconductor Inc.
英文描述： 2.5G Multimode Transceiver
中文描述： 2.5G的多模收發(fā)器
文件頁數(shù)： 9/56頁
文件大小： 392K
代理商： ZL20250
ZL20250
Data Sheet
9
Zarlink Semiconductor Inc.
1.1 Receive Path
There are two IF inputs which will receive an input signal from IS136/AMPS and GSM IF filters. The differential input
stages are identical and are followed by an agc amplifier. Gain control is provided from an external analogue voltage.
After the agc amplifier the signal is then down-converted either to a low IF frequency or baseband and the signal flow
then depends on the mode selected. All internal signals are differential. The LO frequency for the down conversion
is derived from an on chip oscillator and PLL. The LO frequency can be programmed to be either oscillator frequency
divided by 2 or 4. When in divide by 2 mode a DLL (Delay Locked Loop) circuit can be selected to maintain accurate
quadrature. It is particularly important to have good quadrature in IS136/AMPS modes using a low IF frequency, to
achieve the required image rejection in conjunction with the following polyphase bandpass filter. It is also possible
to programme high side or low LO injection. Each receive mode will now be described in more detail
1.1.1 IS136
The IS136 receive signal path is shown in detail in Figure 4 and performance for each stage is summarized in the
following table.
The output of the agc amplifier is down-converted using a quadrature mixer to a low IF of 60kHz. High side or low
side LO injection can be selected. The In Phase (I) and Quadrature (Q) signals at 60 kHz are then passed through
anti alias filter stage to remove any high frequency signals prior to subsequent sampling. The 60 kHz IF signals are
then fed into a switched capacitor polyphase bandpass filter which not only provides filtering but also provides image
rejection. This switched capacitor filter provides very stable performance and no calibration is required. After the
bandpass filter the 60 kHz IF signal is further amplified and then mixed down to baseband I and Q signals. Additional
filtering is required at baseband to remove spurii from the down-converter. This filtering is provide in two stages, the
first stage is a switched capacitor filter with the second stage being a smoothing filter to remove clock breakthrough
from the preceding switched capacitor filter. The differential baseband outputs can then be fed directly into analogue
to digital converters on a baseband processor.
Circuit
Block
Gain
(dB)
Filter
Bandwidth
(If Applicable)
Description
IF Input (IF0)
26
max
Differential IF input stage
AGC Amplifier
AGC Amplifier - Gain control range 90dB
Quadrature
Down-converter
47
Down-conversion to 60kHz IF
Anti-alias filter
230 kHz
Low pass Butterworth (n= 3)
Band Pass Filter
+/- 20 kHz
Switched capacitor polyphase Chebyshev. Also
provides typically 30 dB image rejection. Centre
frequency = 60 kHz. Clock frequencies 1.44 MHz and
720 kHz.
Gain Stage
Baseband Down-converter
7
Down conversion to baseband I and Q signals
Baseband filter 1
37.5 kHz
Switched capacitor low pass Chebyshev. Clock
frequency = 240 kHz
Baseband filter 2
60 kHz
Smoothing filter. Low pass Butterworth
Table 1 - IS136 Receive Gain and Filter Distribution
相關PDF資料
PDF描述
ZL20250LCE 2.5G Multimode Transceiver
ZL20250LCF 2.5G Multimode Transceiver
ZL30100QDG1 T1/E1 System Synchronizer
ZL30100 T1/E1 System Synchronizer
ZL30100QDC T1/E1 System Synchronizer
相關代理商/技術參數(shù)
參數(shù)描述
ZL20250/LCE 制造商:Microsemi Corporation 功能描述:RF TRNSCVR FM 56QFN - Bulk
ZL20250/LCF 制造商:Microsemi Corporation 功能描述:RF TRNSCVR FM 56QFN - Bulk
ZL20250LCE 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:2.5G Multimode Transceiver
ZL20250LCF 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:2.5G Multimode Transceiver
ZL20B 制造商:YEASHIN 制造商全稱:YEASHIN 功能描述:500 mW DO-35 Hermetically Sealed Glass Zener Voltage Regulators
發(fā)布緊急采購，3分鐘左右您將得到回復。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*