=20
In a message dated 27/02/2005 13:59:22 GMT Standard Time, =20
dcrice@............ writes:

Switched capacitor filters are  very nice to work with, easy to design and=20
control, but they have limited  dynamic range, typically less than 80 dB. No=
w=20
that=E2=80=99s a lot if you=E2=80=99re just  looking at an analog trace, but=
 only equivalent to=20
a 12 or 13 bit A/D  converter. If anybody is using a 16-bit or one of the=20
24-bit delta-sigma  converters, you should use digital filtering to maintain=
 your=20
dynamic range.  Doug Crice


Hi Doug,
=20
    Or use analogue filters? You can download a filter  calculation program=20
called Filterpro from the Texas website=20
_http://focus.ti.com/analog/docs/sampleutilities.tsp?path=3Dtemplatedata/cm/=
utilities/data/filterpro&templateId=3D3&family
Id=3D57&navigationId=3D9742_=20
(http://focus.ti.com/analog/docs/sampleutilities.tsp?path=3Dtemplatedata/cm/=
utilities/data/filterpro&templateId=3D3&familyId=3D57&navigat
ionId=3D9742)=20
    Switched capacitor filters should come with a  wealth warning notice....
=20
    Regards,
=20
    Chris Chapman






In a message dated 27/02/2005 13:59:22 GMT Standard Time,=20
dcrice@............ writes:
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>
  
Switched capacitor filters a=
re=20
  very nice to work with, easy to design and control, but they have limited=20
  dynamic range, typically less than 80 dB. Now that=E2=80=99s a lot if you=
=E2=80=99re just=20
  looking at an analog trace, but only equivalent to a 12 or 13 bit A/D=20
  converter. If anybody is using a 16-bit or one of the 24-bit delta-sigma=20
  converters, you should use digital filtering to maintain your dynamic rang=
e.=20
  Doug Crice=


Hi Doug,
 
    Or use analogue filters? You can download a fil=
ter=20
calculation program called Filterpro from the Texas website http://focus.ti.com/analog/docs/sampleutilities.tsp?path=
=3Dtemplatedata/cm/utilities/data/filterpro&templateId=3D3&familyId=
=3D57&navigationId=3D9742
    Switched capacitor filters should come with a=20
wealth warning notice....
 
    Regards,
 
    Chris Chapman