@sia@home
100+ Head-Fier
- Joined
- Oct 31, 2004
- Posts
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Hi guys, I have a uni project atm. I'm not directly asking for spoiler help but.
Me and my partner are building a wireless IR speaker/headphone audio transmitter.
http://www.eed.usv.ro/misc/mirrors/c...s/circ0173.htm
We have to change the design extensivly, and the first thing to go is the ca3237e chip. From datasheets I have calculated the the expected gain from that chip the way its configured is about 101.2dB, yes decibels, not Gain as a ratio.
Basically I know I could do a 2 stage feedback loop similar to theirs using 2 chips off an opamp, just say OPA2227U, which is what we are going to do.
But then it comes down as using 2 feedback loops with R2=1M ohm, and R1 = 2.5kohms.
I know there is an alternative way to do the feedback loop, I still remember from first year it looked something like this
I know the formula is going to be relatively simple. ie (r1 + r2 / r3)+1 but that is only doubling the gain and we need a gain value around 800 to keep this constant with the original data.
Does anyone else think that 101.2dB sounds quite rediculous?
Any help or comments or alternative feedback loops would be greatly appreciated.
Me and my partner are building a wireless IR speaker/headphone audio transmitter.
http://www.eed.usv.ro/misc/mirrors/c...s/circ0173.htm
We have to change the design extensivly, and the first thing to go is the ca3237e chip. From datasheets I have calculated the the expected gain from that chip the way its configured is about 101.2dB, yes decibels, not Gain as a ratio.
Basically I know I could do a 2 stage feedback loop similar to theirs using 2 chips off an opamp, just say OPA2227U, which is what we are going to do.
But then it comes down as using 2 feedback loops with R2=1M ohm, and R1 = 2.5kohms.
I know there is an alternative way to do the feedback loop, I still remember from first year it looked something like this
I know the formula is going to be relatively simple. ie (r1 + r2 / r3)+1 but that is only doubling the gain and we need a gain value around 800 to keep this constant with the original data.
Does anyone else think that 101.2dB sounds quite rediculous?
Any help or comments or alternative feedback loops would be greatly appreciated.