HMC445 PCB Layout Recommendations

Hi there, 

I apologize for the delay in getting back to you. The correct part number is HMC445 and the link appears to be working now. I recommend that users that can not find a file using the UltraLibrarian search tool located at the bottom of the Symbols and Footprints web page submit a request to have a symbol made as this helps everyone. Once the symbol is ready (typically a few days) it will be emailed to you and added to the library. It doesn't appear that this was done so I went ahead and requested a footprint. 

Another option is to use the menu on the left side of the page and access the 'Package Index'. First locate the correct package type, Hittite Legacy LFCSP in this case.  Next find the correct package by noting the outline drawing and part number (LP4 indicates a 4mm plastic QFN package). Next, note the number of pins, 24 in this case as well as the nominal size of the 'Exposed Pad' (EP). There are only 2 choices for a 24 lead, QFN (4x4mm w/2.8mm ep). At this point you'll need to open both options and compare them to the package outline drawing (POD) shown in the datasheet. These 2 options are identical except for the pad size for the leads. The outline drawing indicates that the HCP-24-2 is the correct footprint (Attached here). 

One could also locate other HMC devices that use the same package (LP4) that have the same POD and search UltraLibrarian for that model but this isn't nearly as efficient and could more easily result in making a mistake. 

 HCP-24-2.pdf  

Best Regards, 

Marty 

Hi there, 

I apologize for the delay in getting back to you. The correct part number is HMC445 and the link appears to be working now. I recommend that users that can not find a file using the UltraLibrarian search tool located at the bottom of the Symbols and Footprints web page submit a request to have a symbol made as this helps everyone. Once the symbol is ready (typically a few days) it will be emailed to you and added to the library. It doesn't appear that this was done so I went ahead and requested a footprint. 

Another option is to use the menu on the left side of the page and access the 'Package Index'. First locate the correct package type, Hittite Legacy LFCSP in this case.  Next find the correct package by noting the outline drawing and part number (LP4 indicates a 4mm plastic QFN package). Next, note the number of pins, 24 in this case as well as the nominal size of the 'Exposed Pad' (EP). There are only 2 choices for a 24 lead, QFN (4x4mm w/2.8mm ep). At this point you'll need to open both options and compare them to the package outline drawing (POD) shown in the datasheet. These 2 options are identical except for the pad size for the leads. The outline drawing indicates that the HCP-24-2 is the correct footprint (Attached here). 

One could also locate other HMC devices that use the same package (LP4) that have the same POD and search UltraLibrarian for that model but this isn't nearly as efficient and could more easily result in making a mistake. 

 HCP-24-2.pdf  

Best Regards, 

Marty