參數(shù)資料
型號(hào)： ZL38065QCG1
廠商： ZARLINK SEMICONDUCTOR INC
元件分類： 數(shù)字傳輸電路
英文描述： 32 Channel Voice Echo Canceller
中文描述： DATACOM, ISDN ECHO CANCELLER, PQFP100
封裝： 14 X 14 MM, 1.40 MM HEIGHT, LEAD FREE, MS-026BED, LQFP-100
文件頁(yè)數(shù)： 11/48頁(yè)
文件大?。?/td> 658K
代理商： ZL38065QCG1
ZL38065
Data Sheet
11
Zarlink Semiconductor Inc.
1.1 Adaptive Filter
The adaptive filter adapts to the echo path and generates an estimate of the echo signal. This echo estimate is then
subtracted from Sin. For each group of echo cancellers, the adaptive filter is a 1024 tap FIR adaptive filter which is
divided into two sections. Each section contains 512 taps providing 64 ms of echo estimation. In
Normal
configuration
, the first section is dedicated to channel A and the second section to channel B. In
Extended Delay
configuration
, both sections are cascaded to provide 128 ms of echo estimation in channel A. In
Back-to Back
configuration
, the first section is used in the receive direction and the second section is used in the transmit
direction for the same channel.
The ZL38065 offers industry leading convergence speeds, both in initial convergence and reconvergence. A
sample test result from G.168-2002 Test 2A can be seen in Figure 5. This test result demonstrates one of the many
conditions where the Zarlink device offer sub 50 ms initial convergence times (G.168 Test 2A, Hybrid 5, 40 ms
delay, ERL=24dB, Lrin=0dBm0). Full G.168 test results across all hybrids and test conditions are available upon
request.
Figure 5 - Sample G.168 Test 2A Convergence Result
1.2 Double-Talk Detector
Double-Talk is defined as those periods of time when signal energy is present in both directions simultaneously.
When this happens, it is necessary to disable the filter adaptation to prevent divergence of the Adaptive Filter
coefficients. Note that when double-talk is detected, the adaptation process is halted but the echo canceller
continues to cancel echo using the previous converged echo profile. A double-talk condition exists whenever the
relative signal levels of Rin (Lrin) and Sin (Lsin) meet the following condition:
Lsin > Lrin + 20log
10
(DTDT)
where DTDT is the Double-Talk Detection Threshold. Lsin and Lrin are signal levels expressed in dBm0.
A different method is used when it is uncertain whether Sin consists of a low level double-talk signal or an echo
return. During these periods, the adaptation process is slowed down but it is not halted. The slow convergence
speed is set using the Slow sub-register in Control Register 4. During slow convergence, the adaptation speed is
相關(guān)PDF資料
PDF描述
ZL40120 Low Power, Current Feedback Quad Operational Amplifier
ZL40120DCA Low Power, Current Feedback Quad Operational Amplifier
ZL40120DCB Low Power, Current Feedback Quad Operational Amplifier
ZL40121 Low Power,Current Feedback Dual Operational Amplifier
ZL40121DCA Low Power,Current Feedback Dual Operational Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ZL38070 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:256 Channel Voice Echo Canceller
ZL38070_06 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:256 Channel Voice Echo Canceller
ZL38070GBG 制造商:Microsemi Corporation 功能描述:256 Ch VEC with enhanced noise matching 制造商:Microsemi Corporation 功能描述:ECHO CANCELLER CHIP 256CH G.164/G.165/G.168/G.711 W/ TONE DE - Trays 制造商:MICROSEMI CONSUMER MEDICAL PRODUCT GROUP 功能描述:IC VOICE ECHO CANCEL 535MCMBGA 制造商:Microsemi Corporation 功能描述:IC VOICE ECHO CANCEL 535MCMBGA
ZL38070GBG2 制造商:Microsemi Corporation 功能描述:ECHO CANCELLER CHIP 256CH G.164/G.165/G.168/G.711 W/ TONE DE - Trays 制造商:MICROSEMI CONSUMER MEDICAL PRODUCT GROUP 功能描述:IC VOICE ECHO CANCEL 535MCMBGA
ZL388 制造商:Velleman Inc 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*