Components size and PCB trace

[dann11]

I am design PCB layout for a PFC controller, and most of the suggested components size is 0603, and these value is not able to me as of the moment. Can I used 0805 or 1206 as a replacement to this 0603 components? what impact will these packaging difference may cause to my design? Or how will I compensate the difference? Can I just resize my trace for components that will be affected by the packaging difference?

 

[barry]

Assuming all other parameters are met (voltage, capacitance, etc.) there's no reason you can't use a larger footprint, unless this is a very high frequency design where size might matter.

 

[c_mitra]

I am design PCB layout for a PFC controller, and most of the suggested components size is 0603?

For a PFC, the suggestion is just random. 1206 is about four times the size, will have greater power rating (just because of the size) and will be easier to handle (for manual soldering). I of course do not know about the real estate, but use the thickest trace width consistent with your layout.

 

[dann11]

Assuming all other parameters are met (voltage, capacitance, etc.) there's no reason you can't use a larger footprint, unless this is a very high frequency design where size might matter.

Assuming all other parameters are met (voltage, capacitance, etc.) there's no reason you can't use a larger footprint, unless this is a very high frequency design where size might matter.

That's one thing I forgot.. I am using a switching frequency of 100K Hz..

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For a PFC, the suggestion is just random. 1206 is about four times the size, will have greater power rating (just because of the size) and will be easier to handle (for manual soldering). I of course do not know about the real estate, but use the thickest trace width consistent with your layout.

with the packaging size, can it also be a consideration to eliminate/generate noise or ringing in the signal especially in High frequency application?

 

[c_mitra]

with the packaging size, can it also be a consideration to eliminate/generate noise or ringing in the signal especially in High frequency application?

100kHz is not really the high frequency where the component size will matter. Not even 1 MHz. Around 100MHz, both component size and the layout and the placements become very critical. But I really doubt that you will need 10-100 MHz for a power factor controller.

You can get a rough idea by using wavelengths instead of frequency. At 3GHz, the wavelength is about 10 cm components that are 1cm or larger must be evaluated carefully. In the same way, you can also consider the time with respect to the period (1 GHz is 1 ns and you need to consider the propagation delays).

 

[Vasilevski]

Hi,
As was mentioned above there are no reasons you can't use 1206 or 0805 in your PCB layout. 100 kHz is quite low frequency and parasitic inductance and capacitance will not cause a significant impact.
Our firm is a manufacturer of the power supplies (1-4kW) that's why we use quite big PCBs and there are no reasons to use small cases smaller then 0805. So we use 1206 and 0805 in our controller boards with frequences around 80kHz.
Usually the smallest trace width we use is 0,3mm. This width is sufficient for reliable soldering and consequent using of a PCB. However if you are able to use more wide traces you should use them. A wide trace has smaller inductance than narrow one.

Denis