- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄98253 > TLV320AIC26IRHB (TEXAS INSTRUMENTS INC) SPECIALTY CONSUMER CIRCUIT, PQCC32 PDF資料下載
參數(shù)資料
| 型號(hào)： | TLV320AIC26IRHB |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 消費(fèi)家電 |
| 英文描述： | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| 封裝： | 5 X 5 MM, GREEN, PLASTIC, QFN-32 |
| 文件頁數(shù)： | 14/67頁 |
| 文件大小： | 883K |
| 代理商： | TLV320AIC26IRHB |
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頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁
TLV320AIC26
SLAS412 DECEMBER 2003
www.ti.com
21
Automatic Gain Control (AGC)
Automatic gain control (AGC) can be used to maintain nominally constant output signal amplitude when recording speech
signals. This circuitry automatically adjusts the PGA gain as the input signal becomes overly loud or very weak, such as
when a person speaking into a microphone moves closer or farther from the microphone. The AGC algorithm has several
programmable settings, including target gain, attack and decay time constants, noise threshold, and maximum PGA gain
applicable that allow the algorithm to be fine tuned for any particular application. The algorithm uses the absolute average
of the signal (which is the average of the absolute value of the signal) as a measure of the nominal amplitude of the output
signal.
Target gain represents the nominal output level at which the AGC attempts to hold the ADC output signal level. The ’AIC26
allows programming of eight different target gains, which can be programmed from 5.5 dB to 24 dB relative to a full-scale
signal. Since the ’AIC26 reacts to the signal absolute average and not to peak levels, it is recommended that the larger
gain be set with enough margin to avoid clipping at the occurrence of loud sounds.
Attack time determines how quickly the AGC circuitry reduces the PGA gain when the input signal is too loud. It can be
varied from 8 ms to 20 ms.
Decay time determines how quickly the PGA gain is increased when the input signal is too low. It can be varied in the range
from 100 ms to 500 ms.
Noise threshold is the minimum amplitude for the input signal that the AGC considers as a valid signal. If the average
amplitude of the incoming signal falls below this value, the AGC considers it as silence and brings down the gain to 0 dB
in steps of 0.5 dB for every FS. It also sets the noise threshold flag. The gain stays at 0 dB until the average amplitude of
the input signal rises above the noise threshold value. This ensures that noise does not get amplified in the absence of a
valid input speech signal. The noise threshold level is programmable between 60 dB and 90 dB relative to full scale. This
operation includes debounce and hysteresis to avoid having the AGC gain cycle from high gain to 0 dB when the signal
amplitude is close to the noise threshold level. When the noise threshold flag is set, the status of the gain applied by the
AGC and the saturation flag should be ignored.
Maximum input gain applicable allows the user to restrict the maximum gain applied by the AGC. This can be used for
limiting PGA gain in situations where environmental noise is greater than the programmed noise threshold. Depending on
the noise threshold setting, the value of the maximum input gain applicable can be programmed between 0 dB and 59.5
dB in steps of 0.5 dB as shown in Table 1.
Table 1. Input Gain Settings
NOISE THRESHOLD
ALLOWED RANGE FOR THE MAXIMUM INPUT GAIN
60 dB
0 dB to 59.5 dB
70 dB
11.5 dB to 59.5 dB
80 dB
21.5 dB to 59.5 dB
90 dB
31.5 dB to 59.5 dB
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TLV320AIC26IRHBG4 | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| TLV320AIC26IRHBRG4 | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| TLV320AIC27CPFB | SPECIALTY CONSUMER CIRCUIT, PQFP48 |
| TLV320AIC27IPFB | SPECIALTY CONSUMER CIRCUIT, PQFP48 |
| TLV320AIC27TPFB | SPECIALTY CONSUMER CIRCUIT, PQFP48 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TLV320AIC26IRHBG4 | 功能描述:接口—CODEC Octal Bus Trnscvr With 3-State Outputs RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel |
| TLV320AIC26IRHBR | 功能描述:接口—CODEC Lo-Pwr Stereo Codec RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel |
| TLV320AIC26IRHBRG4 | 功能描述:接口—CODEC Lo-Pwr Stereo Codec RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel |
| TLV320AIC27 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:STEREO AUDIO CODEC |
| TLV320AIC27CPFB | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Texas Instruments 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。