Voltage Regulator Help (Eagle Capacitor Help: Looking for correct SMD capacitor)

Thread Starter

ElectEng

Joined Sep 3, 2019
42
Hello everyone,

I am trying to copy this circuit using the LM7809.
9V Regulator.png

If this is connected directly to my 12V 70 Ah solar battery will I encounter any issues using SMD components? I plan to place a heatsink on the LM7809 chip. Looking on Digikey, should I buy a 16V 0.33uF ceramic capacitor for C1 and 16V 0.1uF for C0?

Also, I am struggling to find the correct surface mount capacitor in the Eagle software. Can I just use small SMD style ceramic capacitors like these:
https://www.digikey.com/product-detail/en/kemet/C0603C334K4RACTU/399-4916-1-ND/1090911
https://www.digikey.com/product-detail/en/samsung-electro-mechanics/CL05F104ZO5NNNC/1276-1004-6-ND/3891518

I am mostly worried about choosing the wrong footprint for the board and not thinking of all the things that could cause damage.
 

nsaspook

Joined Aug 27, 2009
6,502
While it's not critical I personally like larger footprint filter caps for regulators and power electronics. It's an area that's likely to be probed with a meter lead during a problem so a 1206 smd capacitor makes a nice test point.
 

SLK001

Joined Nov 29, 2011
1,532
Hello everyone,

I am trying to copy this circuit using the LM7809.
View attachment 187692

If this is connected directly to my 12V 70 Ah solar battery will I encounter any issues using SMD components? I plan to place a heatsink on the LM7809 chip. Looking on Digikey, should I buy a 16V 0.33uF ceramic capacitor for C1 and 16V 0.1uF for C0?

Also, I am struggling to find the correct surface mount capacitor in the Eagle software. Can I just use small SMD style ceramic capacitors like these:
https://www.digikey.com/product-detail/en/kemet/C0603C334K4RACTU/399-4916-1-ND/1090911
https://www.digikey.com/product-detail/en/samsung-electro-mechanics/CL05F104ZO5NNNC/1276-1004-6-ND/3891518

I am mostly worried about choosing the wrong footprint for the board and not thinking of all the things that could cause damage.
Any of the 16+V parts will work for your circuit.

As for the footprints, you'll be money ahead if you just create your own. I don't think that I have ever used any stock footprint for any of my SMD devices (or thru hole device for that matter).
 

Thread Starter

ElectEng

Joined Sep 3, 2019
42
Any of the 16+V parts will work for your circuit.

As for the footprints, you'll be money ahead if you just create your own. I don't think that I have ever used any stock footprint for any of my SMD devices (or thru hole device for that matter).
Thanks.
I'll do some research in the morning to find out how to make my own footprint. Do you have any tips?
 
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