## [Gumstix-users] Power supply voltage for a gumstix...

 [Gumstix-users] Power supply voltage for a gumstix... From: Chris Parker - 2007-02-07 22:09:40 ``` I am trying to figure out if I can power my gumstix directly from my battery, or if I need to go through my voltage regulator on the board that it will be talking to. On http://docwiki.gumstix.org/Power_jack , it says at the bottom that voltages higher than 5v into the jack can damate the gumstix. However, the schematic shows a MIC5255, which is a 5V regulator. So, Do I need to regulate my power before the power jack, or will the Gumstix take care of it for me. My batteries are 6.5~7V NiMH. -Chris ```

 [Gumstix-users] Power supply voltage for a gumstix... From: Chris Parker - 2007-02-07 22:09:40 ``` I am trying to figure out if I can power my gumstix directly from my battery, or if I need to go through my voltage regulator on the board that it will be talking to. On http://docwiki.gumstix.org/Power_jack , it says at the bottom that voltages higher than 5v into the jack can damate the gumstix. However, the schematic shows a MIC5255, which is a 5V regulator. So, Do I need to regulate my power before the power jack, or will the Gumstix take care of it for me. My batteries are 6.5~7V NiMH. -Chris ```
 Re: [Gumstix-users] Power supply voltage for a gumstix... From: Patrick Doyle - 2007-02-07 22:31:45 ```On 2/7/07, Chris Parker wrote: > I am trying to figure out if I can power my gumstix directly from my > battery, or if I need to go through my voltage regulator on the board > that it will be talking to. On http://docwiki.gumstix.org/Power_jack , > it says at the bottom that voltages higher than 5v into the jack can > damate the gumstix. However, the schematic shows a MIC5255, which is a > 5V regulator. So, Do I need to regulate my power before the power jack, > or will the Gumstix take care of it for me. My batteries are 6.5~7V NiMH. > According to the data sheet for the MIC5255, it has an absolute maximum input voltage rating of 7V. This means the part will blow up if you put more than 7V into it. (Not really, but you can't blame Micrel for what happens if you _do_ put more than 7V in it. Perhaps it will reformat your hard drive :-)) It has an operating range of 2.7V to 6V. This means that they guarantee the performance of the device over that range. I'd drop the battery voltage down to 5V if I were you. --wpd ```
 Re: [Gumstix-users] Power supply voltage for a gumstix... From: Dave Hylands - 2007-02-07 22:38:04 ```Hi Chris, On 2/7/07, Chris Parker wrote: > I am trying to figure out if I can power my gumstix directly from my > battery, or if I need to go through my voltage regulator on the board > that it will be talking to. On http://docwiki.gumstix.org/Power_jack , > it says at the bottom that voltages higher than 5v into the jack can > damate the gumstix. However, the schematic shows a MIC5255, which is a > 5V regulator. So, Do I need to regulate my power before the power jack, > or will the Gumstix take care of it for me. My batteries are 6.5~7V NiMH. It depends. Which cards do you have? The robostix can probably take it, although it depends on the cards used with a connex. The're all linear regulators, so anything abov what's required needs to be disappated as heat. How many NiMH cells are you talking about? They're nominally 1.2v each, but can be as high as 1.5v when fully charged. IIRC, NiMH cells are depleted around 1v. So with a robostix, 5 cells would range between 5v (depleted) and 7.5v (fully charged). With a waysmall, 4 cells would range between 4v (depleted) and 6v (fully charged). Both of those ranges should be fine. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ ```