Does the LT3029 regulator give out 9v 500mA without external circuitry needed for it?... I'm planning to use it for my arduino mega... I really haven't used that regulator before ...My main power source for my whole circuit is 12V 2Amps, that's really big for the microcontroller so ill be using a regulator to power it up. I also need suggestions on what regulator should be fit for arduino mega...please help me ...thanks

  • \$\begingroup\$ "The onboard linear regulator will be doing too much work so I'm going to throw another linear regulator at it." Argh. \$\endgroup\$ – Ignacio Vazquez-Abrams Jul 21 '15 at 2:18
  • \$\begingroup\$ well yah... the onboard regulator in arduino mega can't take 2amperes ...the board will get burned.. and i don't wanna destroy it ...what regulator would you suggest \$\endgroup\$ – Alyzha Orejudos Jul 21 '15 at 2:22
  • \$\begingroup\$ There's no way the Mega will be chewing up 2A, but you should be using a switching regulator to bring the supply down to 5V unless you know you can't use one. \$\endgroup\$ – Ignacio Vazquez-Abrams Jul 21 '15 at 2:23
  • \$\begingroup\$ One of my classmates tried to use 2A 9v ...those little capacitors on the board exploded... that's horrible ...9volts is safe right? but yeah board wont take 2A it'll only get what current it needs.. but it depends on its resistance level to limit the current going in ...and dude i guess it can't resist 2Amperes \$\endgroup\$ – Alyzha Orejudos Jul 21 '15 at 2:29
  • \$\begingroup\$ If the cap exploded then they hooked the supply up backwards; caps are voltage-sensitive (and some are polarity-sensitive), not current-sensitive. \$\endgroup\$ – Ignacio Vazquez-Abrams Jul 21 '15 at 2:30

You say LT3069 in the title, but LT3029 in the text. I assume you mean LT3029 since the LT3069 seems to be rare, at least as a regulator.

The answer is in the datasheet. No it does not work with zero external components, it needs at least six total components for a single output. It's also a pretty unfriendly part to work with unless you have a premade PCB or proper equipment (DFN with 0.45mm pitch or MSOP with 0.5mm pitch- and it's expecting a ground plane for heat dissipation).

All measurements were taken in still air on a four-layer FR-4 board with 1oz solid internal planes, and 2oz external trace planes with a total board thickness of 1.6mm.

But you don't need it- according to the official web page for the Mega:

Input Voltage (recommended) 7-12V

So, 12V is within the recommended range. The 2A is sufficient. The microcontroller board will draw what it needs (and no more) when connected correctly. You only need to worry about the current if you plan on drawing a lot of current from the I/O pins or from the internal regulator.

Edit: LOL I put that "when connected correctly" in there before seeing your comment on your classmate. It's kind of important.

  • \$\begingroup\$ Ok i'll try wiring it with the transformer but what if it gets really hot? \$\endgroup\$ – Alyzha Orejudos Jul 21 '15 at 2:57
  • \$\begingroup\$ If it gets too hot to hold your finger on the regulator (about 60°C based on my calibrated index finger- YFMV) it's a bit too hot. You could use an LM7809 or buy a Chinese switchmode module to reduce the voltage. \$\endgroup\$ – Spehro Pefhany Jul 21 '15 at 3:06

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