LP3 Footprint for Genesys
Im designing a circuit in Genesys. The main component of this circuit will be the Hittite HMC548LP3 LNA. The data sheet for the component is below:
http://www.hittite.com/content/docum.../hmc548lp3.pdf
The problem i am facing now is getting the layout footprint for the LNA. It is a LP3 - 3 x 3 mm QUAD FLATPACK NO-LEAD (QFN) package. The package outline can be found here:
http://www.hittite.com/content/docum...ckage_info.pdf
I cant seem to find the footprint layout for this type of package for the Genesys software (dxf/gerber format). Im not sure how to design the footprint myself as I've never been taught how to do so and have no experience in it whatsoever. I dont want this issue messing up my project. I was hoping someone could tell me where I could possibly find this footprint or maybe even help me out with it. It would be greatly appreciated!
I'll give it a try later this afternoon... rain is pouring down and nothing on telly.
Added after 2 hours 30 minutes:
Phew...
Took a while to sort it out. This is my first try on that footprint. Note you have to make sure you attach the correct pins to port. Maybe it will be simpler to delete the em-ports not in use, but the document you showed was just a physical description, not how your specific part would use the pins.
NOTE, this is footprint is NOT verified and may contain errors. Do check that it will work, I do not warranty anything!:D
Good Luck
Please note I made a revision of the footprint...
it is always difficult to have groundplane and ports to work. Genesys has always had a pretty poor layout machine, causing all sorts of problems especially when filling with groundplane. Try the new footprint in version 2. Should work better.
As for the part, d/l the datasheet, and realized it is two amps with-in a single 3x3 mm package. Apparently you intend to use the filter in between. Somehow it does not make sense to use a large harpin filter and then put the input and output within 3 mm just to use one tiny chip. I would look into using two amps, why not look at the MiniCircuits ERA amps, should be so much easier to interface. Maybe to use a Hittite 374?
Many thanks for that! I shall have a look over it soon.
Yes the size of the amp and filter being vastly different is one of the issues that Im facing. I was told to use this amp by my project supervisor due to its dual stage amplification process. Would using two amps(ie one before and one after the filter) have a similar performance. I will have a look at the amps you have suggested though and see if it suits my needs. Cheers
Hi again,
Im having trouble importing the .lib file into Genesys. When i try to load a library into it the only file type it accepts is .xml. Ive tried looking all over the manual and internet for a way to load it but i havent found anything. Could you please guide me on how to do this.
As for your suggestion of using another amp, I looked at the Hittite 374 but the gain isnt very good at 2.2 GHz, which is the frequency im looking at. As for the minicircuits ERA ones, the NF is quite high for these types. Are there any other Amps that are similar to the Hittite 548 that you might know of?
Lastly, I was wondering what the IP3 of the amp stands for. I reasearched on the net and found this article:
http://www.ppraa.org/downloads/tech_...pt%20Point.doc
This article was the one that helped me understand the best but they are refering to receivers/mixers. Can the same theory be applied to the amplifiers as well. Thanks very much.
You can ignore the question about loading the .lib file. I just figured it out :)
Put the lib-file in the library folder... and then when you choose footprint for new component placed in layout you can open my library! You can not import from main Geneysy menu :)
My thought was that you use two amps, but in separate packages, one with low noise but not that high IP3, in front of the filter and the last one will not need to be that low noise but higher IP3. But it also depends on how many signals you will have outside the bandpass filter, maybe the first amplifier will have troubble if not linear enough.
Using two Hittite 374 should be perfect, will give about 4 dB higher gain, and 0.2 dB less noise figure. Much much simpler to realize and it is possible to assemble yourselfe too
IP stands for Intercept point and is a way of measuring the linearity of a component, amplifier or mixer (or any component really) It indicates at what point (hypotetical) the distortion will be as strong as the real input (or output) signal. Distortion will increase faster than the real signals, hence they will intercept in amplitude... but in real life you will burn the component long before this. So it is really a calculated value, which will allow you to compare different components for linearity.
Added after 34 minutes:
I have now run some simulations, and the result is shown in the attached plots.
First the bare filter, and to get a good passband I had to run optimize, from the M-filter tab. This will give good passband but you will not meet the goal in stop band, missing with a few dB.
Second plot is with the HMC384 dual amp, something strange shows up, as the S11 does go wild around 2155 MHz, and the gain is increasing around this frequency.
Thirdl plot I did replace the 384 with two HMC374, one at each end of the filter. This looks pretty good, and should work OK.
I have not run any EM simulation on this!
Cheers