ADS8668: ADS8668 practical input range

Alireza Khalilian

Part Number: ADS8668

Hello,

I just have a simple question to ask. I just wanted to know whether I would face any problem if I use the ADS8668 for converting 10mV-50V Analog to Digital, does this 12 bit ADC support this range or not. I know it is 12bit and it is theoretically possible, I just wanted to make sure that I would not face any issue in practice and I would not need to use any extra component..

Regards,

Alireza

over 5 years ago

0 Dale Li over 5 years ago

TI__Mastermind 46235 points

Hi Alireza,

ADS8668 can not support your signal range directly, this ADC can support input signal up to bipolar +/-10.24V or unipolar 10.24V. Also, the lowest input range is +/-0.64V or unipolar 1.28V. You have to use external signal conditioning circuit to adjust your signal to proper range of ADC or switch the range with external front-end circuit. There is one way which can be used to extend the input range of ADC by reducing your large signal with resistor divider, see following application notes for more information including error analysis, just for your reference.

Circuit to increase input range on an integrated analog front end (AFE) SAR ADC (Rev. A)

Reducing effects of external RC filter circuit on gain and drift error

Extending Input Voltage Range and Understanding Associated Errors for ADC With I

Regards,

Dale

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ADS8668: ADS8668 practical input range