SRC4392: Using one input only, no output?

Graham North1

Part Number: SRC4392

Tool/software:

Hi,

If I only want to use one input on the SRC4392 is there anything I should do in the hardware design with the un-used inputs?

If I'm not using the output at all is there anything I should do in the hardware design with the un-used output pins?

If mute is only being done through the I2C interface, can I connect the MUTE input pin directly to GND?

Is it ok to tie the I2C address pins (A0 & A1) directly to VIO or GND without resistors?

Thanks,

over 2 years ago

0 Sam Yang over 2 years ago

TI__Intellectual 1870 points

Hi Graham,

1. You can tie the un-used inputs to GND. Be careful of the CPM mode as different logic levels can change between SPI and I2C mode.

2. The output pins can be left floating.

3. Yes, if you are using a I2C interface to control the mute function, the MUTE pin can be tied to GND to ensure it does not interfere with the software control.

4. Yes, you can tie these pins directly to VIO or GND without resistors. Digital inputs have high impedance and do not draw significant current, so it is safe to do this.

In general, any un-used analog input pins should be tied to GND to prevent picking up noise. Thanks.

Regards,

Sam

0 Graham North1 over 2 years ago in reply to Sam Yang

Intellectual 415 points

Hi,

Thanks for your reply.

Please can you explain what you mean by:

Sam Yang said:
Be careful of the CPM mode as different logic levels can change between SPI and I2C mode

Thanks,

0 Sam Yang over 2 years ago in reply to Graham North1

TI__Intellectual 1870 points

Hi Graham,

The CPM pin is an input pin and the condition determines I2C or SPI mode according to page 10 of the datasheet. Thanks.

Regards,

Sam

0 Graham North1 over 2 years ago in reply to Sam Yang

Intellectual 415 points

Ah, yes. I'm pulling CPM high for I2C mode.

0 Sam Yang over 2 years ago in reply to Graham North1

TI__Intellectual 1870 points

Hi Graham,

Great, thanks. Please let me know if you have any more questions.

Regards,

Sam

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SRC4392: Using one input only, no output?