Best 3.3V regulator

[joe61]

I'm got a Blue SMiRF and am in the process of wiring it up, learning how it works, etc. Since it needs 3.3V input I'm wondering what a good voltage regulator would be for it. I'll probably be powering it from the MCU 5V output. TX and RX signals will go through a Sparkfun level converter, also powered by the 3.3V regulator.

I have a TI regulator, but I'm wondering what other people use here for this.

Thanks

Joe

[Soeren]

Hi,

Any 3.3V LDO regulator capable of delivering the current you need should do fine.
Remember to follow the data sheet recommendations for capacitors on input and output.

[Admin]

I'm got a Blue SMiRF and am in the process of wiring it up, learning how it works, etc. Since it needs 3.3V input I'm wondering what a good voltage regulator would be for it. I'll probably be powering it from the MCU 5V output.

Are you sure you read the Blue SMiRF datasheet correctly?

I see:

Operating Voltage: 3.3V-6V

 

[joe61]

I'm got a Blue SMiRF and am in the process of wiring it up, learning how it works, etc. Since it needs 3.3V input I'm wondering what a good voltage regulator would be for it. I'll probably be powering it from the MCU 5V output.

Are you sure you read the Blue SMiRF datasheet correctly?

I see:

Operating Voltage: 3.3V-6V

Yes, it says that, and it fooled me for a while too :-( Unfortunately, it's not that uncommon for Sparkfun to get things wrong on their product pages. However, their tutorial on the smirf says

"1) Power and logic are 3.3V, no more.  There's no regulator on the device, so don't deviate from the spec.  And yes, that's the voice of experience talking."

http://www.sparkfun.com/tutorials/67

Also, the Roving Networks data sheet for the bluetooth IC shows a maximum voltage of 3.6V.

http://www.rovingnetworks.com/documents/RN-41.pdf

I'm only hoping their description of the level shifter is correct, but I've done some measurements on a breadboard and it seems to work as advertised.

Thanks

joe


-- Edit --

Doh! I was looking at the wrong module in the tutorial. It does say the Blue SMiRF has a voltage regulator in it.

Never mind ...

Joe (slinking back under a rock).

[joe61]

Hi,

Any 3.3V LDO regulator capable of delivering the current you need should do fine.
Remember to follow the data sheet recommendations for capacitors on input and output.

Thanks. I'll just go with what I have if there aren't any big differences.

Joe

[Admin]

Yes, it says that, and it fooled me for a while too :-( Unfortunately, it's not that uncommon for Sparkfun to get things wrong on their product pages. However, their tutorial on the smirf says

"1) Power and logic are 3.3V, no more.  There's no regulator on the device, so don't deviate from the spec.  And yes, that's the voice of experience talking."

http://www.sparkfun.com/tutorials/67

-- Edit --

Doh! I was looking at the wrong module in the tutorial. It does say the Blue SMiRF has a voltage regulator in it.

Never mind ...

Joe (slinking back under a rock).

You're definitely in the right for not trusting the SF datasheets, I find them occasionally wrong. SF makes changes between batches, and they often do not update the documentation/schematics/specs to reflect the changes. That said, I've always powered my Blue SMiRFs with 5V . . . and only had one out of the three I own mysteriously fry . . .

Anyway, straight from the link you posted:

the Blue SMiRF's have voltage regulators on them so you can power them with 5V, and the I/O lines are 5V tolerant.