TLV320DAC3120: MISSING REFERENCE DESIGN

Hi, Kamil,

Welcome to E2E and thank you for your interest in our products!

All the information about the TLV320DAC3120 evaluation board is located in the User's Guide:

www.ti.com/.../slau302.pdf

Could you provide more details about the voltage spikes issue?
- Does this problem appear all the time?
- Have you verified if these spikes appear at the power supplies?
- Could you provide a schematic to have a better approach to this issue?

I recommend to verify if the following recommendations are being respected in your design:

e2e.ti.com/.../3377.common-noise-issues-in-codecs

Best regards,
Luis Fernando Rodríguez S.

Hi Luis,

I'm trying to play short time signals and spikes appear when amplitude of signal is greater than 0.
Spikes don't appear at the power supplies.
I make separated GNDs for digital part, analogue part and output class-D stage. GNDs are connected together by ferrite.

Best Regards,

Kamil

Hi, Kamil,

Could you provide your schematic and register configuration, please? This is to have a better approach to this issue.

Thank you.

Best regards,
Luis Fernando Rodríguez S.

Hi Luis,

This is register config:
tlv320dac3120_reset();

tlv320dac3120_i2c_write(1,1); // soft reset
delay_ms(1);
tlv320dac3120_i2c_write(4,7); // clk_select
tlv320dac3120_i2c_write(6,20); // pll_j_set
tlv320dac3120_i2c_write(5,147); // pll_p_r_set
delay_ms(10); // delay after pll set
tlv320dac3120_i2c_write(11,140); // ndac power up
tlv320dac3120_i2c_write(12,132); // mdac power up
tlv320dac3120_i2c_write(13,0); // dosr msb set
tlv320dac3120_i2c_write(14,1); // dosr lsb set
tlv320dac3120_i2c_write(60,4); // minidsp set
tlv320dac3120_i2c_write(51, 36); // setting ouput of dac_fs on gpio1
tlv320dac3120_i2c_change_page(8);
tlv320dac3120_i2c_write(1,5); // adapt filter set
tlv320dac3120_i2c_change_page(1);
tlv320dac3120_i2c_write(38,128); // analog vol set to full power
tlv320dac3120_i2c_write(31,20); // common mode voltage
tlv320dac3120_i2c_write(32,134); // class D amp power up
tlv320dac3120_i2c_write(35,64); // class D amp routing
tlv320dac3120_i2c_change_page(0);
tlv320dac3120_i2c_write(27,32); // 24 bit sample resolution
tlv320dac3120_i2c_write(63,146); // dac init data & power up
tlv320dac3120_i2c_write(64,4); // dac unmute

And schematic:
s29.postimg.org/.../tlv.png

Best Regards,

Kamil

Hi, Kamil,

Could you try two more things?

- Could you power down the Class-D amplifier?
- Could you replace the ferrites by 0-ohm resistors?

Please let me know if the problem persists.

Best regards,
Luis Fernando Rodríguez S.

Hi Luis,

I tried it before and it didn't change my problem.
Have you any idea?
Maybe you can send me any pcb layout design of this product?

Best regards,
Luis Fernando Rodríguez S.

Hi, Kamil,

Do you have additional devices/IC that may be generating these voltage spikes? I mean, could you power down your additional devices to verify the root cause? Additionally, have you tried to change the codec power supplies?

You may base your design on our ACEV-1A EVM:

www.ti.com/.../slau302.pdf

Best regards,
Luis Fernando Rodríguez S.

Hi Luis,

I checked it before i wrote about help.
Can you answer me if you have a pcb design layout for this product?

Best regards,
Kamil