[参考译文] TLV320AIC3206：在 BLE 上的每次暂停和恢复流式传输后、音频逐渐变得嘈杂

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请注意，本文内容源自机器翻译，可能存在语法或其它翻译错误，仅供参考。如需获取准确内容，请参阅链接中的英语原文或自行翻译。

https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1031194/tlv320aic3206-audio-getting-progressively-noisy-after-each-pause-and-resume-of-streaming-over-ble

器件型号：TLV320AIC3206

我们通过 I2S 接口和 nRF52840主控制器将压电式触点麦克风与 TLV320AIC3206编解码器搭配使用。以16位11025Hz 的频率对音频进行采样、并通过 BLE/USB 传输到 Android 应用。编解码器一直在运行、在暂停期间接收到的数据被丢弃。从断电开始、无论录制时间有多长、录制环境有多安静或多安静、一切都能正常工作。但是、每次暂停并通过 BLE 恢复流式传输后、音频都会逐渐产生噪声。尽管我有一个高通滤波器、但有时还有直流偏移。但是、如果我点击麦克风、噪音就会消失、但如果我暂停并再次录制、它将再次逐渐发出噪音。但是、这不是通过 USB 流式传输实现的。我不使用自动增益控制。请帮助我解决此问题。

以下是寄存器配置的核心部分：

        { 0x00, 0x00 },  // Page 0


        { 0x12, 0x83 },  // Power up NADC with 3 div
        { 0x13, 0x85 },  // Power up MADC with 5 div

        { 0x51, 0x42 },  // Power up Right ADC channels
        { 0x54, 0x28 },  // Right Digital Volume 20db

        //fine tune gain page 114
        { 0x52, 0x00 },  // Reg 82: Unmute Left and Right ADC Digital Volume Control
        //page 115
        { 0x56, 0x00 },  // disable left AGC



        { 0x00, 0x01 },  // Page 1

        { 0x01, 0x08 },  // Disable weak AVDD to DVDD connection
        { 0x02, 0x00 },  // Enable master analog power control

        
        { 0x0A, 0x40 },  // Set input common mode to 0.75V
        { 0x3D, 0x04 },  // Select ADC PTM_R4

        { 0x7B, 0x01 },  // Set REF charging time to 40ms
        { 0x34, 0x00 },  // IN1L not routed to LEFT_P
        { 0x36, 0x00 },  // do not Route Common Mode to LEFT_M

        { 0x37, 0x04 },  // Route IN3R to RIGHT_P with 10K input impedance
        { 0x39, 0x40 },  // Route Common Mode to RIGHT_M with impedance of 10K by CM1R
        { 0x3C, 0x5f },  // Reg 60: Unmute Right MICPGA, Gain selection 47.5dB
 
        
    	{ 0x00, 0x00 },  // Page 0
	//page 114
        { 0x51, 0x41 },   // Power up Right ADC channels
                          // ADC Volume Control Soft-Stepping Control
                            // 00: ADC Volume Control changes by 1 gain step per ADC Word Clock
                            // 01: ADC Volume Control changes by 1 gain step per two ADC Word Clocks

	//page 115
        { 0x54, 0x10 },   // Right Digital Volume 8db

	//fine tune gain page 114
        { 0x52, 0x80 },   // Reg 82: Unmute Right ADC Digital Volume Control
	//page 115
	    { 0x56, 0x00 },   // disable left AGC

30Hz 高通滤波器设置：

codec_biquad_cfg_30hz[] =
{

/*

Text "* Sample Rate = 11025"
Text "* Filter 5 High Pass 2nd Order Butterworth, 30 Hz Fc 0.0 dB "

Text "* BQ: H(z) = (N0 + 2*N1/z + N2/(z2)) / (8388608 - 2*D1/z - D2/(z2))"
Text "* Filter Coefficients in format N0, N1, N2, D1, D2"

Text "* 1O: H(z) = (N0 + N1/z) / (8388608 - D1/z)"
Text "* Filter Coefficients in format N0, N1, D1"

Text "* Filter 5 BQ "
0x7E762C
0x8189D4
0x7E762C
0x7E73CF
0x830EEB
*/


 
        {0x00, 0x00},  // set page 0
        {0x3d, 0x05},  // PRB_R5 selected (Page 0, Register 61)
     
        {0x00, 0x09},  // set page 9

// BIQUAD A
        {0x2C, 0x7e},  // C39 (Pg 9, Reg 44,45,46)
        {0x2D, 0x76},  //
        {0x2E, 0x2c},  //

        {0x30, 0x81},  // C40 (Pg 9, Reg 48,49,50)
        {0x31, 0x89},  //
        {0x32, 0xd4},  //

        {0x34, 0x7e},  // C41 (Pg 9, Reg 52,53,54)
        {0x35, 0x76},  //
        {0x36, 0x2c},  //

        {0x38, 0x7e},  // C42 (Pg 9, Reg 56,57,58)
        {0x39, 0x73},  //
        {0x3A, 0xcf},  //

        {0x3C, 0x83},  // C43 (Pg 9, Reg 60,61,62)
        {0x3D, 0x0e},  //
        {0x3E, 0xeb},  //

        


};

以下是编解码器的原理图、暂停时的波形正在恢复：