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Using ADS1282 with a single ended output signal accelerometer

Bayron Andres Calvache
Prodigy 10 points
Other Parts Discussed in Thread: ADS1282, PGA281

I am interesting in use ADS1282 ADC with an accelerometer with single ended signal output.
The accelerometer range output is: +/-7.5V @+/-2G. I consider use the PGA281 to attenuate the signal.

What connection configuration is more recommendable por this kind of sensor?

I have a little confusion with the absolute input range. In the case of single ended signal, what are the max and min limits?

I appreciate your help.

Regards,

Bayron Calvache

  • 0
    TI__Mastermind 44680 points
    Hi Bayron,

    Welcome to the TI E2E Forums!

    You ought to be able to connect the accelerometer directly to the PGA281, so long as the supply rails and input common-mode voltage are set properly. The input range of the PGA281 would be limited by the VSP and VSN supply voltages. Neither input signals should be within 2.5V of either supply rail, so be sure to provide sufficient headroom. If this connection is single-ended (i.e. "INN" is connected to ground) then VSN will need to be supplied with a negative voltage of at least -2.5V (or a more negative voltage).

    You would likely use the PGA281 in a gain configuration of 1/4 or 1/8 (V/V), depending on your intended reference voltage for the ADS1282. The ADS1282's input range is set by the reference voltage and its own internal PGA gain. Let's assume the ADS1282's PGA is configured for a gain of 1 V/V... In this case, the ADC's input voltage range is +/- (Vref/2).

    Therefore, a 2.5V reference would allow for a +/- 1.25V signal (the PGA281 would need to be configured for a gain of 1/8)
    OR
    a 5V reference would allow for a +/-2.5V signal (the PGA281 could be configured for a gain of 1/4).

    I hope that gives you a starting point for your design!

    Best Regards,
    Chris