Where can I find a SMD 9v regulator? - Page 1
Forum section: electronics / projects

author: tim1986
author_rank: Newbie
timestamp: March 12, 2013, 03:18:53 am
content: Where can I find a SMD 9v regulator? I have looked on mouser and it is difficult to find one that can handle 2 amps. Any suggestions?Thank you,-Tim

author: c4757p
author_rank: Super Contributor
timestamp: March 12, 2013, 03:23:45 am
content: Linear, you mean? I wouldn't be doing 2A in a linear SMD regulator. If you insist on it, use an LM317 with an external pass transistor, but I recommend a TO-220 with a decent-sized heat sink. What about a buck converter?

author: Psi
author_rank: Super Contributor
timestamp: March 12, 2013, 03:26:13 am
content: Lets assume you have an input voltage of 12V.12V input - 9V output = 3V drop3V * 2A = 6WThink about the size of a typical mains soldering iron (they use around 12W)They're massive size-wise compared to a SMD component and still get above 300deg C.Burning off 6W of heat is almost impossible for a SMD package with only the copper as a heatsink.Even a DPak with large copper plane is going to get very hot trying to burn off 6W

author: mariush
author_rank: Super Contributor
timestamp: March 12, 2013, 04:00:01 am
content: http://www.digikey.com/product-detail/en/BA90DD0WHFP-TR/BA90DD0WHFPCT-ND/3663770http://www.digikey.com/product-detail/en/MIC29302WU%20TR/576-1125-1-ND/771851http://www.digikey.com/product-detail/en/LT1085IM%23PBF/LT1085IM%23PBF-ND/2107524http://www.digikey.com/product-detail/en/MIC39152WD%20TR/576-3615-1-ND/2339541MIC29302, MIC29303, LT1085, MIC39152 ... there's plenty... but like the above person says.. 2 amps is a big value... if you go with a ldo that has a low voltage drop like the micrel regulators above which have 0.37v you can then use a low input voltage, for example 10vWith others that need 1-1.3v above the output, to get 2 A output you'd waste 2-4 watts as heat and that's hard to dissipate on pcb.Consider getting TO-220 and screwing it to the pcb with a heatsink between the pcb and the to-220 package, maybe even a small copper plate on the back side.

author: Eonir
author_rank: Contributor
timestamp: March 12, 2013, 07:40:24 am
content: The crucial question is: why SMD?If it's because you want to manufacture a board and save some money by not drilling many holes, then that's one issue. If it's because you're short on space, then that's another. As mentioned above, linear regulators require adequate heatsinking. That will inevitably take a lot of space.You can either use a simple linear regulator with a power transistor for handling the current, or perhaps find a chip that could be paralleled. You might also use something like the LM150 which can handle more current.You could also turn to simple switching regulators. These can handle as much current as you'd like, provided you don't cheap out on the inductor, Schottky diode, and capacitors. The whole setup could have a very small footprint if you design it properly.____________________________________________________________Just in case you were trying to search for a regulator that's hard-wired to output 9V, learn about adjusting the output voltage of your voltage regulator. I have attached an image that shows how to do it. To obtain 9V output, simply adjust your resistors accordingly.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 12, 2013, 09:19:04 am
content: If you want 2A in SMD you need to be doing it with a switching regulator.

author: richcj10
author_rank: Unknown
timestamp: March 12, 2013, 02:55:58 pm
content: Why not use two one amp regulators?It depends on how the circuit is designed if that is possible.