Benjamin wrote on Nov 11th, 2008, 9:41pm:I am wanting to find the fastest response regulator for a low supply level. Specifically I would like as fast as possible response with w.c. supply of 1.35V, when the output voltage is target at 1.3V.
So what's the fastest option for such small headroom.
If necessary perhaps I could take the current efficiency hit and use a pumped voltage for the diffAmp supply voltage, but not the output driver.
Any suggestion appreciated?
Thanks, Benjamin
Hi,
You can use the textbook LDO scheme. Everything runs on low voltage supplies, and you pump the gate of the output driver which is an NMOS. This has very fast response since it acts like a source follower. Obviously, it is better if you have a triple-well technology that you can tie source-bulk of this NMOS.
The 50 mV drop might be a bit of an issue, especially if you also need high-temperature operation. But give it a try.
I guess you are using an LDO to tame a widely varying supply.
Regards,
Vivek