From: Dave H. <dhy...@gm...> - 2008-05-27 18:37:07
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Hi Stephen, > 1) In this stack, I should power the Robostix, (with at least 6V to accommodate voltage regulator headroom), and not power the NetMMC card. Yeah - although the voltage regulator only needs about 1/2v of room, and will work on 5v as well (you just get 4.5v to the robostix - not optimal but it should work fine. > 2) Having multiple MIC5219 regulator chips (on different daughterboards) connected to the 3.3V rail, with only one of them powered, is not a cause for concern. Well, the rail which is shared between the boards is valled V_BATT, and with the robostix, it's powered from a 5v regulator. Each daughtercard which needs 3.3v will have its own regulator and use V_BATT as the input and create its own 3.3v source. > 3) If I put an SD card in the MMC/SD socket, the power consumption of the NetMMC board may exceed the 500 ma rating of the Robostix 3.3V regulator, requiring some additional measures to power the system (such as powering the NetMMC as well, or using a higher-rated voltage regulator for the 3.3V rail in place of the Robostix' MIC5219). I've never had any issues with using an SD or CF (memory) card in a robostix/connex/netMMC or netCF stack. It's when you use the wifi module that you start running into issues. -- Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ |