Author Topic: Input and output impedance of a push pull amplifier using MRF300AN, MRF300BN  (Read 1463 times)

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Offline kopcicleTopic starter

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So I woke up one day to the the NXP MRF300 and started pushing pixels...
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Offline kopcicleTopic starter

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« Last Edit: March 23, 2020, 08:16:05 pm by kopcicle »
"If a man wants to carry two cats home by their tails, by all means let him. He’ll learn things that he might not have otherwise even guessed, and the experience will be one he’ll not soon forget!"

~S. Clemens
 

Offline T3sl4co1l

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Hmm, no ground support in the middle?  I guess there's going to be another layer under that.

Tim
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Offline profdc9

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RF MOSFETs usually have the case as the source rather than the drain, and so the transistors can be connected directly to a heatsink below and the heatsink can be grounded.  Of course, any anodizing has to be removed from the heatsink to make contact.
 

Offline T3sl4co1l

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Yeah, that's the case here.  I'm thinking the source pin may end up soldered to bottom side copper somehow (e.g. loose copper foil?).  Bottom side copper being clamped (preferably with help of EMI gasket) to the heatsink (non anodized, as mentioned!) would be okay as well.

Tim
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Offline kopcicleTopic starter

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Tim

More or less nearly correct. The MRF300 AN has a companion part with the gate and drain pins swapped. The source is the center pin as well as the tab.
This makes for easy mounting as well as layout.
"If a man wants to carry two cats home by their tails, by all means let him. He’ll learn things that he might not have otherwise even guessed, and the experience will be one he’ll not soon forget!"

~S. Clemens
 


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