Messages in this thread | | | Date | Fri, 25 Sep 2015 09:47:26 -0700 | From | Mark Brown <> | Subject | Re: Voltage setting on chained regulators, how? |
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On Fri, Sep 25, 2015 at 11:07:24AM +0200, Sascha Hauer wrote:
> Any idea how such a scenario could be implemented? The regulator > framework already has some idea of supply regulators, but it only takes > care of en/disabling the supplies and will not change the voltage on the > supplies. Should this be implemented in the regulator framework? Some > first experiments brought me into a locking hell quite fast.
It's just a case of implementation, but yes the locking is fun. I don't think it's that big a deal to rethink it, it's partly complicated since the existing locking is designed to be really simple and easy to review.
> For added fun ideally we want to put the LDOs in bypass mode instead of > configuring them for minimum dropout. The bypass mode doesn't work for > the 1.2GHz operating point though since the ripple on the switching > regulator gets too high. So we can't just statically configure bypass > mode but have to enable it dynamically based on the operating points.
I suspect you always want the LDO in there to clean the supply up, it's just a more serious issue when more power is being drawn. Having a DCDC doing most of the voltage drop for efficiency with a LDO to clean up the output of the DCDC is pretty common. [unhandled content-type:application/pgp-signature] | |