Author Topic: range switching on a multi-op amp (extended bandwidth) gain stage  (Read 1129 times)

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Offline SArepairmanTopic starter

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So I need to do range switching on an input signal that is multiplied to high gains using a op-amp cascade to increase bandwidth. I need four ranges.

One way I thought to do it is to just put four op-amps with the same gain and tap them off with switches, so I can select the output of OPA1,2,3,4.
The other way is to use many more switches (I guess 4 per op amp, which is not THAT bad, and this way I don't need four OPA (the gain bandwidth product requirement is satisfied with 2 op amps really).

Have you guys seen either of these methods used in actual designs?  I am not worried about the op-amp noise in particular. Using four equal gain op-amps and tapping them off seems like the best solution even though I only need two.

I need at least two op-amps, unless you have a 20 GHZ op amp.
« Last Edit: March 02, 2014, 08:07:17 pm by SArepairman »
 


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