ADS1219: When to Use External REFs: Is an Internal REF Necessary?

Koji Hayashi92

Mastermind 7030 points

Part Number: ADS1219
Other Parts Discussed in Thread: REF6245,

Tool/software:

Hi TI team,

I will use External REF on AIN0, AIN1.

AIN0 and AIN1 connect the differential output of a sensor that operates within 4.5V.

AIN2 and AIN3 are connected to the output of sensors that operate within 2.048V of the internal REF (voltage divider resistor for high voltage monitor, temperature sensor).

Are there any concerns about using external REF for AIN2 and AIN3 as well ?

Best Regards,

Koji

3 months ago

0 Bryan Lizon86 3 months ago

TI__Guru 52156 points

Hi Koji Hayashi92,

How do you plan to measure a 4.5V signal using a 2.048V reference? Can you provide a diagram of your system so I can understand and provide better recommendations?

-Bryan

0 Koji Hayashi92 3 months ago in reply to Bryan Lizon86

Mastermind 7030 points

Hi Bryan

Thank you for reply.
I would not measure a 4.5V signal using a 2.048V reference.
I plan to use an external VREF of 4.5V (REF6245) for 4.5V signals.
I would like to know if there are any concerns about using an external VREF instead of the internal VREF of 2.048V for other sensors.

Best Regards,
Koji

0 Bryan Lizon86 3 months ago in reply to Koji Hayashi92

TI__Guru 52156 points

Hi Koji Hayashi92,

No there is no issue using an external VREF with the ADS1219. Ensure that you meet the requirements in the Recommended Operating Conditions in the datasheet

-Bryan

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ADS1219: When to Use External REFs: Is an Internal REF Necessary?