Christopher Hoover wrote: > Agreed, that that regulator doesn't have sufficient margin for the entire > TADD-1. > > I was suggesting using the low-noise high PSRR linear reg only to establish > the bias level. > > There are indeed better parts. This one looks pretty good for an > integration solution (not include three C's): > > http://datasheets.maxim-ic.com/en/ds/MAX6126.pdf > > This app note, which filters the MAX6126 with an additional pass transistor > and opamp, shows how to get down to 6 nv/sqrt(hz): > > http://www.maxim-ic.com/appnotes.cfm/appnote_number/3657 > > Chris
A simpler solution should be possible. Since both the input and the outputs are transformer coupled, the circuit ground plane could sit at half the supply voltage. There need be little dc current flowing into or out of the circuit ground plane so a simple resistive divider should suffice to bias it at the desired voltage. If all RF loads within the circuit are returned to the circuit ground plane then most of the resistive dividers used to set opamp input dc levels can be eliminated. This complicates testing in that either a floating dc input supply would be necessary or differential probes with adequate common mode rating would be required. Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
