Function Generator Output Boost

Thread Starter

rcbuck

Joined Nov 10, 2009
10
I have built a function generator using the XR-2206. I am getting a little over 2 volts output for the sine wave. The circuit is running on +/- 9V supplies. What would be the best way to increase the output to around 5 volts and drive a 50 ohm load? That would be around 1/2 watt output. Possibly a voltage amplifier followed by an emitter follower?

Ray
 

KL7AJ

Joined Nov 4, 2008
2,229
I have built a function generator using the XR-2206. I am getting a little over 2 volts output for the sine wave. The circuit is running on +/- 9V supplies. What would be the best way to increase the output to around 5 volts and drive a 50 ohm load? That would be around 1/2 watt output. Possibly a voltage amplifier followed by an emitter follower?

Ray
Check out video distribution amps.

http://www.opamplabs.com/407g.htm

You can probably build one cheaper, but this will allow you to spend your time doing something more productive. :)

eric
 
Last edited:

Thread Starter

rcbuck

Joined Nov 10, 2009
10
He could have bought a function generator if he wanted to be more productive.:D
How true, but what is the fun in being productive? I will probably do something like is shown in National Semiconductor AN-272.
 

SgtWookie

Joined Jul 17, 2007
22,221
You might consider something like a video opamp, like an LM6171.

Avnet Express sells those in a SOIC-8 (surface mount) package for about $1.75. They're out of the 8-DIP packages until December.

You could also use a high-speed low-power opamp with a gain of 2.5, and back it up with a power buffer like an LT1010; it'll source/sink up to 150mA.
 

Thread Starter

rcbuck

Joined Nov 10, 2009
10
You might consider something like a video opamp, like an LM6171.
I did some research after my last post and decided to try the LM6181 since I can run it on +/-15V supplies. Order has already been placed with DigiKey.
 
I will have a HP 3011A Function generator refurbished soon. If interested I can sell it cheaper than any listed on Ebay. I bought this unit - It came DOA and I was told to keep it. They sent me free another replacement generator that did work.

I decided to repair the DOA unit. Replaced all the power supply components and installed a modern on/off Neon lamp instead of the old flickering NE-2H. I did not check calibration.

This generator is capable of sending 0 -30 volts peak to peak to its output.

If anyones interested let me know what its worth to you after you check whats for sale on Ebay.

Tom
 

KL7AJ

Joined Nov 4, 2008
2,229
I'm jaded about a few things. Since I worked in TV broadcasting, video DA's tend to reproduce like coat hangers in a neglected closet. :) I've never had to pay for any of these!

Incidentally, Op-Amp Labs makes some fantastic modules for this sort of thing....almost anything from DC to Daylight. Most of their stuff is in OCTAL socket form...just add power!


Eric
 
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