On 1/25/18 7:17 PM, Joseph Gwinn wrote:
On Thu, 25 Jan 2018 21:13:44 -0500, [email protected] wrote:
Message: 2
Date: Thu, 25 Jan 2018 16:16:59 -0500
From: John Ackermann N8UR <[email protected]>
To: [email protected]
Subject: Re: [time-nuts] Slightly OT: interest in a four-output,
ultra-low jitter, synthesizer block?
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8; format=flowed
Yes, I was planning to include bypasses, and I've been convinced to put
at least the 1.8V regulator on the board as well. And to think about
the interconnects.
What I've seen widely done in circuits requiring low phase noise is to
have a cascade of regulators, all but the last one (that feeds the RF
component in question) beings switchers of different switching
frequency, with simple low-pass filters between the regulators, and
between the last regulator and the RF component being powered.
Between the filtration due to the regulators and that due to the
LPFs, one can achieve very large ripple and noise attenuations.
What we've done is switcher from wide range bus (9-24V) to 8V, 60 dB
ultimate attenuation low pass, switcher 8V to 5V(e.g.), 60 db low pass,
linear with great HF rejection (i.e. the LT3042) to 3V
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
