- 您现在的位置：买卖IC网 > PDF目录98254 > TLV320AIC32IRHBR (TEXAS INSTRUMENTS INC) SPECIALTY CONSUMER CIRCUIT, PQCC32 PDF资料下载
参数资料
| 型号： | TLV320AIC32IRHBR |
| 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： | 20/80页 |
| 文件大小： | 1270K |
| 代理商： | TLV320AIC32IRHBR |
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页第14页第15页第16页第17页第18页第19页当前第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页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页
AUTOMATIC GAIN CONTROL (AGC)
www.ti.com ............................................................................................................................................. SLAS479C – AUGUST 2005 – REVISED DECEMBER 2008
power down, the PGA soft-steps the volume to mute before shutting down. A read-only flag is set whenever the
gain applied by PGA equals the desired value set by the register. The soft-stepping control can also be disabled
by programming a register bit. When soft stepping is enabled, the audio master clock must be applied to the part
after the ADC power down register is written to ensure the soft-stepping to mute has completed. When the ADC
powerdown flag is no longer set, the audio master clock can be shut down.
An automatic gain control (AGC) circuit is included with the ADC and can be used to maintain nominally constant
output signal amplitude when recording speech signals (it can be fully disabled if not desired). 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.
Note that completely independent AGC circuitry is included with each ADC channel with entirely independent
control over the algorithm from one channel to the next. This is attractive in cases where two microphones are
used in a system, but may have different placement in the end equipment and require different dynamic
performance for optimal system operation.
Target gain represents the nominal output level at which the AGC attempts to hold the ADC output signal level.
The TLV320AIC32 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 device 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 gate threshold determines the level below which if the input speech average value falls, AGC considers it
as a silence and hence brings down the gain to 0 dB in steps of 0.5 dB every FS and sets the noise threshold
flag. The gain stays at 0 dB unless the input speech signal average rises above the noise threshold setting. This
ensures that noise does not get gained up in the absence of speech. Noise threshold level in the AGC algorithm
is programmable from –30 dB to –90 dB relative to full scale. A disable noise gate feature is also available. This
operation includes programmable debounce and hysteresis functionality to avoid the AGC gain from cycling
between high gain and 0 dB when signals are near the noise threshold level. When the noise threshold flag is
set, the status of gain applied by the AGC and the saturation flag should be ignored.
Maximum PGA gain applicable allows the user to restrict the maximum PGA gain that can be applied by the
AGC algorithm. This can be used for limiting PGA gain in situations where environmental noise is greater than
programmed noise threshold. It can be programmed from 0 dB to +59.5 dB in steps of 0.5 dB.
Copyright 2005–2008, Texas Instruments Incorporated
27
Product Folder Link(s): TLV320AIC32
相关PDF资料 |
PDF描述 |
|---|---|
| TLV320AIC32IRHBRG4 | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| TLV320AIC32IRHBT | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| TLV320AIC32IRHBTG4 | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| TLV320AIC32IRHB | SPECIALTY CONSUMER CIRCUIT, PQCC32 |
| TLV320AIC33IGQER | SPECIALTY CONSUMER CIRCUIT, PBGA80 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TLV320AIC32IRHBRG4 | 功能描述:接口—CODEC Lo-Pwr Stereo Codec w/6 Inp 6 Otp 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 |
| TLV320AIC32IRHBT | 功能描述:接口—CODEC Lo-Pwr Stereo Codec w/6 Inp 6 Otp 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 |
| TLV320AIC32IRHBTG4 | 功能描述:接口—CODEC Lo-Pwr Stereo Codec w/6 Inp 6 Otp 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 |
| TLV320AIC33 | 制造商:BB 制造商全称:BB 功能描述:LOW POWER STEREO AUDIO CODEC FOR PORTABLE AUDIO/TELEPHONY |
| TLV320AIC33EVM | 功能描述:音频 IC 开发工具 Dghtr card only RoHS:否 制造商:Texas Instruments 产品:Evaluation Kits 类型:Audio Amplifiers 工具用于评估:TAS5614L 工作电源电压:12 V to 38 V |
发布紧急采购，3分钟左右您将得到回复。