- 您现在的位置：买卖IC网 > PDF目录98253 > TLV320AIC26IRHB (TEXAS INSTRUMENTS INC) SPECIALTY CONSUMER CIRCUIT, PQCC32 PDF资料下载
参数资料
| 型号： | TLV320AIC26IRHB |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 消费家电 |
| 英文描述： | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| 封装： | 5 X 5 MM, GREEN, PLASTIC, QFN-32 |
| 文件页数： | 14/67页 |
| 文件大小： | 883K |
| 代理商： | TLV320AIC26IRHB |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页当前第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页
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
相关PDF资料 |
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 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TLV320AIC26IRHBG4 | 功能描述:接口—CODEC Octal Bus Trnscvr With 3-State Outputs RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel |
| TLV320AIC26IRHBR | 功能描述:接口—CODEC Lo-Pwr Stereo Codec RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel |
| TLV320AIC26IRHBRG4 | 功能描述:接口—CODEC Lo-Pwr Stereo Codec RoHS:否 制造商:Texas Instruments 类型: 分辨率: 转换速率:48 kSPs 接口类型:I2C ADC 数量:2 DAC 数量:4 工作电源电压:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:DSBGA-81 封装:Reel |
| TLV320AIC27 | 制造商:TI 制造商全称: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: |
发布紧急采购，3分钟左右您将得到回复。