PGA step, why small step is needed?

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yolande_yj

Joined: 20 Jan 2005
Posts: 146

10 May 2006 17:19 PGA step, why small step is needed?

I see that some RF and IF PGA (programmable gain amp) have resolution as fine as 0.2dB use in application such as DVB-T. I wonder the need of such fine step. Why such a fine step is needed? What is the purpose of this?

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RFDave

Joined: 18 Feb 2004
Posts: 346
Helped: 45
Location: NE USA

11 May 2006 3:23 Re: PGA step, why small step is needed?

Using available parts? For a receive only application, you shouldn't need AGS steps better than 2 or 3 dB, fading is going to be bigger than that.

Dave