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ADS1115: about Input range

Part Number: ADS1115
Other Parts Discussed in Thread: ADS1113, , ADS1114

Hi,

I have a question about input range. It says

~

Description

The ADS1113, ADS1114, and ADS1115 devices (ADS111x) are precision, low-power, 16-bit, I2C-compatible, analog-to-digital converters (ADCs) offered in an ultra-small, leadless, X2QFN-10 package, and a VSSOP-10 package. The ADS111x devices incorporate a low-drift voltage reference and an oscillator. The ADS1114 and ADS1115 also incorporate a programmable gain amplifier (PGA) and a digital comparator. These features, along with a wide operating supply range, make the ADS111x well suited for power- and space-constrained, sensor measurement applications.

The ADS111x perform conversions at data rates up to 860 samples per second (SPS). The PGA offers input ranges from ±256 mV to ±6.144 V,

but,

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)

MIN MAX UNIT
Power-supply voltage VDD to GND –0.3 7 V
Analog input voltage AIN0, AIN1, AIN2, AIN3 GND – 0.3 VDD + 0.3 V

~

Why input range is different 3.description and 7.1Abs...? I think 7.1 abs is correct, so why 3.desc range are +-6.144V?

Please explain(or show the documents) this reason.

thanks,

  • Hello,

    The absolute maximum ratings describe the input range for the analog inputs that will ensure the device is not damaged. Exceeding the absolute maximum could potentially result in damage to the device and will void the other specifications from the datasheet. 

    The input range described in section 3 match the recommended operating conditions from the specifications section. These are the conditions under which the specifications are valid. There is some margin between the recommended operating conditions (where the specifications are valid) and the absolute maximum ratings (where damage may occur), but it is not recommended to operate the device in that range.

    Regards,

    Scott