TAS5755M: No output from Amp

Adam,

This is my own hardware but it's based on the TAS5575MEVM board - part of my schematic is attached.  I switch the +12V to the PVdd supplies via a FEt as part of the power up and, the first time, this obeys the rule of...

"Ramp up PVDD to at least 8 V while ensuring that it remains below 6 V for at least 100 μs after AVDD/DVDD reaches 3 V. Then wait at least another 10 μs."

which is on P62 of the datasheet  (para 10.2.1.2.4.1 Initialization Sequence) but, if I recycle the power, the 4 x 100 uF caps on PVdd hold it at over 6 volts for several minutes so the +12V supply is maintained by the caps even though the +3.3V may disappear.  Is this a big issue?  Might it have damaged the Amps? Do I need to add circuitry to discharge the caps as part of the power initialization?

Ted

The complete part number of the TLV320 is TLV320ADC and it's configured by the following routine...

void setupTLV320(void)
{   
    UART_UartPutString("Setting up TLV320.. ");
    // the values and the order they are written in is taken from page 79-81 of DS (para 11.2.2.2)
    I2C_Write1(TLV320_ADDR, 0x00, 0x00); // set TLV320 to page 0
    I2C_Write1(TLV320_ADDR, 0x01, 0x01); // trigger soft reset the TLV320 will come out of reset on its own
    CyDelay(100);                        // but it needs time so wait 0.1 seconds for device (may be unecessary)
    // table 1 on page 23 of DS gives parameters
    // MCLK = 12 MHz, P=1, R=1, J=7, D=5264, Achieved Fs = 44.1 kHz
    I2C_Write1(TLV320_ADDR, 4, 0x03);        // p47 - Clock comes in on MCLK, CODEC_CLKIN = PLL_CLK       
    I2C_Write1(TLV320_ADDR, 5, 0x11);        //       P = 1, R = 1
    I2C_Write1(TLV320_ADDR, 6, 0x07);        //       J = 7
    I2C_Write2(TLV320_ADDR, 7, 0x14, 0x90);  //       D = 5264 = 0x1490 (Note this sends 2 bytes out in 1 write)
    I2C_Write1(TLV320_ADDR, 5, 0x91);        //       Pwr on to PLL and P = 1, R = 1
    I2C_Write2(TLV320_ADDR, 18, 0x88, 0x82); // p48 - NADC Pwr On and Val = 8, MADC Pwr On and Val = 2 (Note this sends 2 bytes out in 1 write)
    I2C_Write1(TLV320_ADDR, 20, 0x80);       //       AOSR = 128    
    I2C_Write1(TLV320_ADDR, 27, 0x0D);       // p49 - I2S, 16 bits, BCLKop WCLKop DoutEn
    I2C_Write1(TLV320_ADDR, 30, 0x88);       // p50 - BCLK N Div on and BCLK = ADC_CLK/8 = 11.2896 MHz/8 = 1.4112 MHz 
    I2C_Write1(TLV320_ADDR, 61, 0x01);       // use PRB 01 (processing block)
    // ### PAGE 1 VALUES ### (p64 onwards)
    I2C_Write1(TLV320_ADDR, 0, 0x01);        // Set register Page to 1
    I2C_Write1(TLV320_ADDR, 51, 0x00);       // p65 - Set MICBIAS to not used (prolly not needed as 0x00 is default value)
    // Program PGA level
    I2C_Write2(TLV320_ADDR, 59, 0x02, 0x02);  // p68 - Set Left, Right Analog  00 = 0dB 0x1E = +15dB (2 locations set)
    // Program routing of inputs/common mode to ADC input
    I2C_Write1(TLV320_ADDR, 52, 0xFC);        // p66 - Left ADC Input selection for Left PGA = IN1L(P) as Single-Ended
    I2C_Write1(TLV320_ADDR, 55, 0xFC);        // p67 - Right ADC Input selection for Right PGA = IN1R(M) as Single-Ended
    // Unmute analog PGAs and set analog gain
    // ### PAGE 0 VALUES ### 
    I2C_Write1(TLV320_ADDR, 0, 0x00);        // set TLV320 back to page 0
    I2C_Write1(TLV320_ADDR, 81, 0xC2);       // Power up ADC channel
//    I2C_Write1(TLV320_ADDR, 82, 0x00);        // Unmute digital volume control and set gain = 0 dB
}

Sorry, the full part number is TLV320ADC3101IRGER, I have also attached pdfs of the relevant parts of the schematic.

Schematic1of3.pdfSchematic3of3.pdf