ADS127L01: Can I reduce number of pull-up and pull-down resistors?

Alexander Borovsky

Part Number: ADS127L01

Can I to connect together static signals? For examples collect together "FILTER1" and "FSMODE" pins and connect those by pull-dowr resistor to GND. And by the same way pulling up the remaining signals using a single resistor?

over 7 years ago

0 Ryan Andrews over 7 years ago

TI__Guru 66466 points

Hello Alexander,

Thanks for your post!

Yes, you can connect the Hardware Mode pins through individual resistors or just a single resistor. The recommendation for a pull-up/pull-down on each pin was to allow for individual control, if necessary.

Best Regards,

0 Alexander Borovsky over 7 years ago in reply to Ryan Andrews

Prodigy 90 points

Thanks for the fast answer, Andrews!
I.e. this pull-up and pull-down resistors are only for flexibility in debugging?

0 Ryan Andrews over 7 years ago in reply to Alexander Borovsky

TI__Guru 66466 points

Debugging and also to allow for variations in board configuration. :)

0 Alexander Borovsky over 7 years ago in reply to Ryan Andrews

Prodigy 90 points

Thanks a lot!
And I then believed that these resistors somehow affect the accuracy of the ADC. I.e. I can even simply connect to GND or VCC without them?

0 Ryan Andrews over 7 years ago in reply to Alexander Borovsky

TI__Guru 66466 points

These resistors should not affect the accuracy of the ADC. They are only needed to define the device configuration.

The Hardware Mode pins can be shorted to the supplies directly if you never plan to change the configuration and if you are not controlling the same pins with an MCU. All Hardware Mode pins will be configured as inputs from the ADC at power-up, so there should not be a concern with conflict from the ADC perspective. However, if you have an MCU connected to the Hardware Mode pins, you would want to use pull-up/pull-down resistors in case the MCU's GPIOs power up in a different state.

Best Regards,

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ADS127L01: Can I reduce number of pull-up and pull-down resistors?