PCM3070: Need advice in the custom pcb

Maciej Marguz

Prodigy 80 points

Part Number: PCM3070
Other Parts Discussed in Thread: PCM5102, DIR9001

Hello Team,

I'm trying to design simple preamp with pcm3070 and 6 inputs (all analog).

Stereo output + sub output (for active subwoofer) using headphone output with opamp buffer.

All inputs are opamp buffered with gain < 1.

On left top I put the 2xLDO for positive and negative supply (+12V and -12V)

Design simple 2 side pcb. Can you advice my design? I know it is not perfect.

best regards

Maciek

over 2 years ago

0 Daveon Douglas over 2 years ago

TI__Mastermind 23760 points

Hi Maciek,

Our CODEC expert is out of office this week so please be patient as his responses are delayed.

Thanks,

0 Maciej Marguz over 2 years ago in reply to Daveon Douglas

Prodigy 80 points

Hi,

no issues, sure I will wait.

Maciek

0 pdjuandi over 2 years ago in reply to Maciej Marguz

TI__Mastermind 29755 points

Hi,

Are you looking for layout review? We can't review layout based on the picture, we will need the board file.

There are guidelines in the datasheet for laying out this part in section 13.

https://www.ti.com/lit/ds/symlink/pcm3070.pdf?ts=1667248473077&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM3070

Regards.

0 Maciej Marguz over 2 years ago in reply to pdjuandi

Prodigy 80 points

Hello pdjuandi,

sure, do you need gerber files or another format? Or just eagle files?

best regards

Maciek

0 pdjuandi over 2 years ago in reply to Maciej Marguz

TI__Mastermind 29755 points

We can try with Gerber but I need the schematic as well pdf for schematic is fine.

I will be reviewing only circuit/trace related to PCM3070.

0 Maciej Marguz over 2 years ago in reply to pdjuandi

Prodigy 80 points

Hi pdjuandi,

I've modified pcb to 4 layers.

Here is a gerber file:pcm3070_input_v6_2022-11-05.zip

and schematic in pdf:

pcm3070_input_v6.pdf

I would like to use pcm5102 as a stereo output. Shall I use external quartz to drive MCLK line or can I use internal PLL of PCM3070?

thanks a lot.

Maciek

0 pdjuandi over 2 years ago in reply to Maciej Marguz

TI__Mastermind 29755 points

Hi,

My comments on schematic:

Recommend to add 0.47uF cap to GND for unused analog input like IN3_L/R
Recommend to change C19 and C20 to 47nF for LPF fc about 33KHz instead of 1.6KHz
Place a 100nF and 10uF cap on LDOIN if it's used
Place a 10uF cap along with the 100nF cap on DVDD
LDO-SELECT either IOVDD or GND
RESET pin is active low so default set it to high, is reset to J1 correct? Should it be in J1 pin 2 instead of 1?
Add 10uF cap to IOVDD along with the 100nF cap, IOVDD level is from 1.1V to 3.6V
Configure your interface pin either to use I2C or SPI
Check the IN1_R buffer circuit especially R67
Recommend to use 0.47uF cap on analog input instead of 1uF
Refer to section 12 of datasheet for power supply recommendation

Maybe the schematic on page 26 of this user guide can be useful:

https://www.ti.com/lit/ug/slau331a/slau331a.pdf?ts=1667845164909&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM3070

For layout, you can refer to section 13.2 of this document.

https://www.ti.com/lit/ds/symlink/pcm3070.pdf?ts=1667841552885&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FPCM3070

Regards.

0 Maciej Marguz over 2 years ago in reply to pdjuandi

Prodigy 80 points

Hi pdjuandi,

Tkanka for review. I will introduce your comments to circuit.

What about pcm5102? Shall i connect external oscillator to mclk or keep it connected directly between pcm3070 and pcm5102¿

Maciek

0 pdjuandi over 2 years ago in reply to Maciej Marguz

TI__Mastermind 29755 points

Hi Arash,

Can you help to review PCM5102?

thanks.

0 Arash Loloee over 2 years ago in reply to Maciej Marguz

TI__Mastermind 27161 points

Hello Maciej

In general PCM510x requires a system clock ,and the system-clock detection circuit automatically senses the system-clock frequency. However if you decide not to use SCK, you can simply ground its pin . In this case PCM5102 starts up expecting an external SCK input, but if BCK and LRCK start correctly while SCK remains at ground level for 16 successive LRCK periods, then the internal PLL starts, automatically generating an internal SCK from the BCK reference.

PCM510x requires the synchronization b/w LRCK and SCK, However does not need a specific phase relation between them. Naturally if you ground SCK pin, you have less routing between the two IC. Either way should work fine. May be a jumper option to switch between the 2 solutions is a good idea too.

Regards,

Arash