From: Josh Koffman <joshybear@gmail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
Sender: "piclist-bounces@mit.edu" <piclist-bounces@mit.edu>
Date: Sun, 14 Jun 2020 12:41:24 -0700
Subject: [EE] Dual Power Input Circuit
Thread-Topic: [EE] Dual Power Input Circuit
Thread-Index: AdZChXZGNW0xCuz6QYmIStRgVWF6SA==
Message-ID:
 <CAD2N_E9J-dS8M_TLEm_iVKxh6nbRgqBGsdTK7cSUxHo0QhmFZQ@mail.gmail.com>
Reply-To: Microcontroller discussion list - Public. <piclist@mit.edu>
Accept-Language: en-US
X-MS-Exchange-Organization-SenderIdResult: Pass
X-MS-Exchange-Organization-PRD: mit.edu
X-MS-TNEF-Correlator:
received-spf: Pass (protection.outlook.com: domain of gmail.com designates
	209.85.166.48 as permitted sender) receiver=protection.outlook.com;
	client-ip=209.85.166.48; helo=mail-io1-f48.google.com;
dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com;
 s=20161025;	h=mime-version:from:date:message-id:subject:to;
	bh=nsPQyHCCK9OdAM2A/oL5AkhlvY16CZyFunInFCCTRSs=;
	b=pzPCD9rjDTDRAJaI2rnmEUSpRfsnZ2TlUemrMbqVHojYYsE3ZX9v3mmhPb9Bh/spzW
	9OMaYKCZXK3kfaaRR/M/YfufdY5Ryyz8ksjJc+CU3PJbwMlVD2BIVh5qhbnFxprMpweG
	c2R5Mji3U0SMMCuteeVAUOLfsRLdgZCuqxDQ1i7Mm7t+77DqiSIVxzZ5tSH+2sIt8iSS
	4P6QkP3MS6D8qFtK3ON9IDeb6cgkTlr/iOUeAYNuoJaCQtYJ8DeNSG+8Bsb8PhwJz6jr
	8S2l+5NuIc7ZZVtMrgGEGkR7IPcI9GcIPn1KAK6qOJL8Ibn9Qn+Cexz1qnHt5ZayFwT+	+20Q==
authentication-results: spf=pass (sender IP is 209.85.166.48)
	smtp.mailfrom=gmail.com; mit.edu; dkim=pass (signature was verified)
	header.d=gmail.com; mit.edu;	dmarc=pass action=none header.from=gmail.com; 
errors-to: piclist-bounces@mit.edu
list-id: "Microcontroller discussion list - Public." <piclist.mit.edu>
list-post: <mailto:piclist@mit.edu>
x-beenthere: piclist@mit.edu
x-mailman-version: 2.1.6
x-received: by 2002:a6b:6414:: with SMTP id
 t20mr24644658iog.101.1592163709687;	Sun, 14 Jun 2020 12:41:49 -0700 (PDT)
x-topics: [EE]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

Hi all,

I am working on a project that will connect via USB to two computers.
In regular operation either or both of the ports will have power
coming through them. If only one is powered, regardless of which one
it is, the entire circuit needs to use the same power.

My current plan is to send the incoming +5V line from each port
through a selector/combiner. I could do this with a diode or, but I
don't really want that voltage drop. I have found the TI TPS2115A
(https://www.digikey.ca/en/products/detail/texas-instruments/TPS2115APWR/65=
2785
) which I believe would also work.

I'm curious if there's another solution using discrete MOSFETs (or
anything really) that might be a better option.

Thanks!

Josh
--=20
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
        -Douglas Adams
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.