Anti-aliasing ADC samples

Hello all,

I have an ADC that samples some analog signal at 1 Msps. The samples
are then processed by a digital logic / software. To avoid aliasing, I
must make sure that signals entering the ADC have no harmonics at > 500
KHz. Is the only way to do it by an analog lowpass filter (i.e. RC)
before the ADC ? I assume that there is no way whatsoever to filter out
the unwanted frequencies digitally after the ADC, since the ADC
sampling itself already got distorted because of aliasing, is this
right ?

And yet, in some places I've seen mentioned digital lowpass filters for
anti-aliasing. How is this possible ?

Thanks

.

Relevant Pages

  • Re: ADC bandwidth and sample rate
    ... My understanding was that with an ADC at 170 MSPS, you'd want analogue filtering to ensure that no signal above 85 MHz reaches the ADC, since anything higher would be aliased to below 85 MHz. ... So one could build a 1.1 GHz equivalent-time sampling scope front-end ...
    (sci.electronics.design)
  • ADC bandwidth and sample rate
    ... My understanding was that with an ADC at 170 MSPS, you'd want analogue filtering to ensure that no signal above 85 MHz reaches the ADC, since anything higher would be aliased to below 85 MHz. ...
    (sci.electronics.design)
  • Re: Pentax K10D - jetzt aber!
    ... von 10 - 100 MSPS kenne ich von keine Hersteller. ...
    (de.rec.fotografie)
  • Re: ADC bandwidth and sample rate
    ... My understanding was that with an ADC ... at 170 MSPS, you'd want analogue filtering to ensure that no signal ... It is possible that your ADC would be used with bandpass filter ...
    (sci.electronics.design)