PCM1795 / Resistor between IREF pin and GND

S.Satoshi

Guru 21685 points

Hi,

Please let me ask about the resistor between IREF pin and GND.

1, Does the value of this resistor affect to output level?

2, How much does the tolerance of +/-3% of this resistor affect to output level if the answer for Q1 is correct?

Best Regards,

Sonoki

over 12 years ago

0 S.Satoshi over 12 years ago

Guru 21685 points

Hi Don-san,

Can I have your any comments within today our time? Please let me know if you need additional information.

Best Regards,

Sonoki

0 S.Satoshi over 12 years ago in reply to S.Satoshi

Guru 21685 points

Hi Don-san,

We need your response within Monday your time. Any comments will be helpful for us.

Best Regards,

Sonoki

0 Dominik Hartl11 over 12 years ago

TI__Guru 62326 points

The resistor on IREF determines the maximum output current. Iout+(max) = Vref/Rref.

Therefore the output current will be affected by the inverse of the resistor tolerance.

0 S.Satoshi over 12 years ago in reply to Dominik Hartl11

Guru 21685 points

Hi Hartl-san,

Thank you for your response.

Do you know the value of Vref? I could not find this parameter in datasheet.

Best Regards,

Sonoki

0 S.Satoshi over 12 years ago in reply to S.Satoshi

Guru 21685 points

Hi Hartl-san,

And also please confirm the recommended range of output current (min/max) or Rref (min/max). I believe that this information should be defined to set the value of Rref.

Best Regards,

Sonoki

0 Dominik Hartl11 over 12 years ago in reply to S.Satoshi

TI__Guru 62326 points

The recommended value of Rref is 10k. This will set the output current range for optimal performance. Please use a 1% resistor or better.

Please do not use a different value as this will affect DAC performance.

If you want to control gain, please adjust the external I/V circuit.

0 S.Satoshi over 12 years ago in reply to Dominik Hartl11

Guru 21685 points

Hi Hartl-san,

Thank you for your recommendation. I recommended to use 10kohm +/-1% or less as Rref. Please let me ask again if I will received further question.

Best Regards,

Sonoki

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PCM1795 / Resistor between IREF pin and GND