參數(shù)資料
型號: AM79Q021JC
廠商: ADVANCED MICRO DEVICES INC
元件分類: 編解碼器
英文描述: PCM CODEC, PQCC44
封裝: PLASTIC, LCC-44
文件頁數(shù): 10/64頁
文件大?。?/td> 911K
代理商: AM79Q021JC
18
Am79Q02/021/031 Data Sheet
Discrimination against 12- and 16-kHz Metering Signals
If the QSLAC device is used in a metering application where 12-kHz or 16-kHz tone bursts are injected onto the
telephone line toward the subscriber, a portion of those tones may also appear at the VIN terminal. These
out-of-band signals may cause frequency components to appear below 4 kHz at the digital output. For a 12 kHz or
16 kHz tone, the frequency components below 4 kHz will be reduced from the input by at least 70 dB. The sum of
the peak metering and signal voltages must be within the analog input voltage range.
Spurious Out-of-Band Signals at the Analog Output
With PCM code words representing a sine wave signal in the range of 300 Hz to 3400 Hz at a level of 0 dBm0 applied
to the digital input, the level of the spurious out-of-band signals at the analog output is less than the limits shown below.
With code words representing any sine wave signal in the range 3.4 kHz to 4.0 kHz at a level of 0 dBm0 applied to
the digital input, the level of the signals at the analog output are below the limits in Figure 6. The amplitude of the
spurious out-of-band signals between 3400 Hz and 4600 Hz is given by the formula:
Frequency
Level
4.6 kHz to 40 kHz
–32 dBm0
40 kHz to 240 kHz
–46 dBm0
240 kHz to 1 MHz
–36 dBm0
A14
14
π f4000
()
1200
----------------------------dBm0
sin
=
0
–10
–20
–30
–40
–50
–28 dB
–32 dB
QSLAC Device Specification
Frequency (kHz)
3.4
4.0
4.6
19256A-013
Level (dBm0)
Figure 6. Spurious Out-of-Band Signals
相關(guān)PDF資料
PDF描述
AM79Q021VC PCM CODEC, PQFP44
AM79Q062JC A/MU-LAW, PCM CODEC, PQCC32
AM80A-048L-050P25 1-OUTPUT 125 W DC-DC REG PWR SUPPLY MODULE
AM8152BDC SPECIALTY INTERFACE CIRCUIT, CDIP48
AMB315218 MOTION SENSOR, XSS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79Q021JC/T 制造商:Advanced Micro Devices 功能描述:
AM79Q021VC 制造商:Advanced Micro Devices 功能描述:
AM79Q02JC 制造商:Advanced Micro Devices 功能描述:
AM79Q031 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Quad Subscriber Line Audio-Processing Circuit (QSLAC) Devices
AM79Q031JC 制造商:Advanced Micro Devices 功能描述: