- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373784 > ZL38065QCG1 (ZARLINK SEMICONDUCTOR INC) 32 Channel Voice Echo Canceller PDF資料下載
參數(shù)資料
| 型號： | 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 |
| 文件頁數(shù)： | 14/48頁 |
| 文件大小： | 658K |
| 代理商： | ZL38065QCG1 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁當(dāng)前第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頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁
ZL38065
Data Sheet
14
Zarlink Semiconductor Inc.
In response to a valid disable tone, the echo canceller must be switched from the Enable Adaptation state to the
Bypass state. This can be done in two ways, automatically or externally. In automatic mode, the Tone Detectors
internally control the switching between Enable Adaptation and Bypass states. The automatic mode is activated by
setting the AutoTD bit in Control Register 2 to high. In external mode, an external controller is needed to service the
interrupts and poll the TD bits in the Status Registers. Following the detection of a disable tone (TD bit high) on a
given channel, the external controller must switch the echo canceller from Enable Adaptation to Bypass state.
1.6 Instability Detector
In systems with very low echo channel return loss (ERL), there may be enough feedback in the loop to cause
stability problems in the adaptive filter. This instability can result in variable pitched ringing or oscillation. Should this
ringing occur, the Instability Detector will activate and suppress the oscillations.
The Instability Detector is activated by setting the RingClr bit in Control Register 3 to “1”.
1.7 Narrow Band Signal Detector (NBSD)
Single or dual frequency tones (i.e., DTMF tones) present in the receive input (Rin) of the echo canceller for a
prolonged period of time may cause the Adaptive Filter to diverge. The Narrow Band Signal Detector (NBSD) is
designed to prevent this by detecting single or dual tones of arbitrary frequency, phase, and amplitude. When
narrow band signals are detected, adaptation is halted but the echo canceller continues to cancel echo.
The NBSD will be active regardless of the Echo Canceller functional state. However the NBSD can be disabled by
setting the NBDis bit to “1” in Control Register 2.
1.8 Offset Null Filter
Adaptive filters in general do not operate properly when a DC offset is present at any input. To remove the DC
component, the ZL38065 incorporates Offset Null filters in both Rin and Sin inputs.
The offset null filters can be disabled by setting the HPFDis bit to “1” in Control Register 2.
1.9 Adjustable Level Pads
The ZL38065 provides adjustable level pads at Rin, Rout, Sin and Sout. This setup allows signal strength to be
adjusted both inside and outside the echo path. Each signal level may be independently scaled with anywhere from
+9 dB to -12 dB level, in 3 dB steps. Level values are set using the Gains register.
CAUTION: Gain adjustment can help interface the ZL38065 to a particular system in order to provide optimum echo
cancellation, but it can also degrade performance if not done carefully. Excessive loss may cause low signal levels
and slow convergence. Exercise great care when adjusting these values. Also, due to internal signal routings in
Back to Back mode, it is not recommended that gain adjustments be used on Rin or Sout in this mode.
The -12 dB PAD bit in Control Register 1 is still supported as a legacy feature. Setting this bit will provide 12 dB of
attenuation at Rin, and override the values in the Gains register.
1.10 ITU-T G.168 Compliance
The ZL38065 has been certified G.168 (1997), (2000) and (2002) compliant in all 64 ms cancellation modes
(i.e., Normal and Back-to-Back configurations) by in-house testing with the DSPG ECT-1 echo canceller tester.
The ZL38065 has also been tested for G.168 compliance and all voice quality tests at AT&T Labs. The ZL38065
was classified as “carrier grade” echo canceller.
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，3分鐘左右您將得到回復(fù)。