What IC is that?

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PPirx
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What IC is that?

Post by PPirx » Fri Jan 26, 2018 10:32 am

I am trying to identify the IC pictured below -- it is tiny ~2mm diameter case and works pretty well in my first rig. I bought it as a kit online, with no reference to manufacturer or viible markings. I plan to use it to develop an RF shield for RasPi, so I am looking for detailed specification etc.

Anybody knows it?

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s2000
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Re: What IC is that?

Post by s2000 » Fri Jan 26, 2018 12:35 pm

It looks like one of those broadband MMIC IC's, the ones I've seen where slightly bigger in diameter (usually 5 or 6mm in diameter) but no doubt they probably do smaller versions now.

https://en.wikipedia.org/wiki/Monolithi ... ed_circuit

OgreVorbis
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Re: What IC is that?

Post by OgreVorbis » Fri Jan 26, 2018 10:25 pm

That is definitely an MMIC. Those aren't bad, but the claim for 500mW output is not true at all. I've searched these MMICs for very long when I was building my transmitter. The most powerful one I've ever seen was from minicircuits and it was just released about a year ago; it does about 300mW, but it is very expensive and the MOQ is very high, so you'll end up spending a ridiculous amount. Their next best one is the PHA-1+ which does ~150mW. ALL other MMICs from other companies do around the same. You won't find one that powerful esp. not in that package. The device package they show there is what all the older MMICs tend to use. The newer/better ones tend to use SOT-89 package.

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Re: What IC is that?

Post by OgreVorbis » Fri Jan 26, 2018 10:37 pm

Interestingly though, you can get about 1W out of a lot of small RF mosfets without much matching compared to the higher power ones.
For example, on ebay you will see a lot of mini broadband amplifier boards claiming 1-2W and when you look at the board you will see a device that looks a lot like an MMIC because of the lack of matching, but it is not; it is a mini RF mosfet in SOT-89 package. Some of these even seem to work with only one cap on the input and output. Of course, this is not elegant and the noise/performance of these is probably not great, but they do seem to work fine as I have tested them myself.

Here is a list of some of these little mosfets you may want to check:
RD01MUS1
RD01MUS2
RQA0009
BLT53A (this one's a bi-polar and hard to find)

I've seen the first two wired up with only two caps and give 500mW.

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Re: What IC is that?

Post by Albert H » Fri Jan 26, 2018 10:44 pm

The MMIC broadband amps exemplify the GIGO principle - if you put a dirty signal in, you'll just get a bigger dirty signal out!

On one production exciter board, we used a dual-gate FET VCO, followed by a dual-gate FET amplifier set up as a gain-leveller into an MMIC (MAR6 as I recall). This gave a couple of hundred milliwatts into a ceramic bandpass filter, which emerged - cleaned up - at 100mW which drove a 2N4427 to 1 Watt exactly. The output of the 2N4427 was monitored with an inductively coupled sensing loop, which fed the amplitude information back to the second stage and guaranteed that the RF off the board was exactly 1000mW at any Band II frequency, without any tweaking needed. The levelling loop was incorporated because I found that the MMICs were a bit variable from batch to batch - their gain could vary quite significantly.
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