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Mail Archives: geda-user/2015/07/21/13:04:54

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X-Recipient: geda-user AT delorie DOT com
Date: Tue, 21 Jul 2015 17:04:29 GMT
From: falcon AT ivan DOT Harhan DOT ORG (Spacefalcon the Outlaw)
Message-Id: <1507211704.AA02900@ivan.Harhan.ORG>
To: geda-user AT delorie DOT com
Subject: [geda-user] [OT] I need help with selecting components
Reply-To: geda-user AT delorie DOT com

Hello fellow free EDA users,

I wonder, would anyone here happen to have some recommendations as to
what parts I can use for the following 3 needs:

1. A pushbutton switch for power-on and reset buttons.  I am building
   a board based on a cellphone chipset, and the power management chip
   has a PWON pin that needs to be connected to GND through a
   pushbutton switch for power-on control.  It's a control signal like
   reset, no actual power flows through it, hence searches for "power
   switch pushbutton" yield the wrong thing - this pushbutton switch
   will never have any significant current flowing through it, so I
   don't need a "hefty" one.

   The board I'm building is meant to be used bare on a lab bench, and
   will never go into any kind of chassis or enclosure.  Would anyone
   here happen to have a recommendation for a pushbutton switch part
   that's appropriate for such an application?  The kind of pushbutton
   switch part one would expect to see used for reset or power-on
   buttons on chip eval boards from vendors?  And if someone here has
   used such a pushbutton switch in his/her boards and already has a
   vetted PCB footprint for it, that would be ever more awesome. :)

2. A simple LED that shines upward from the board.  Again, I'm looking
   for the kind of LED one would expect to see on a random chip
   vendor's eval board that is meant to be used bare on a lab bench,
   without fitting to any enclosure or chassis.  Ditto regarding a PCB
   footprint to go with it.

3. What would be a "good" or "reasonable" connector to use for
   connecting a lab bench power supply?  The chipset I'm using was
   made for cellphones, and expects to be powered from a Li-ion
   battery.  My board will be powered from a lab bench power supply
   emulating such a battery: on a typical lab bench power supply one
   can tune the voltage (test low and high battery voltage conditions)
   and see how much current the load draws under different conditions.
   I expect my board to draw up to perhaps 2.5 A of current during GSM
   radio Tx bursts - I don't really know to be honest, but those are
   the figures I've seen stated in some places as to how much DC a
   cellphone Tx power amplifier can draw.

   Would anyone here happen to have an idea as to what might be an
   appropriate connector to use for this power input connection?
   Assume 5.5 V max for the voltage rating and 2.5 A max for the
   current rating.  (No, I don't expect to draw 2.5 A at 5.5 V, rather
   I meant them as independent maxima.)

TIA for any help,
SF

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