[sdiy] Powering ICs from a Voltage Divider

[John Luciani]

On Thu, Oct 15, 2009 at 6:53 AM, Justin Owen <juzowen at googlemail.com> wrote:
> Hello,
>
> I have a circuit powered by an LM713 VReg, outputting 12V DC. I have an optocoupler (6N138) that wants 5V VCC and a DAC (TLV5168) that I'm (probably) going to power from 3V VCC.
>
> Is there any reason why I shouldn't run two separate two resistor/voltage dividers from the 713, buffer each of them with an op-amp and power the chips off of that?

If your circuits are low enough currents to power from an op-amp why
not just add a TO-92 regulator?

If your DAC is the TLV5618 and you run it at 3V your reference will
need to be around 1.2V or so. The TLV5618 has a voltage
doubler on the output. If you have 5V you may want to run the DAC off
of 5V. Of course if you only wanted a 2.5V span for
the 12bits then nevermind ;)

(* jcl *)

-- 
You can't create open hardware with closed EDA tools.

twitter: http://twitter.com/jluciani
blog:    http://www.luciani.org