I have seen National LMH6702 current-feedback video amplifier chips in non-inverting amplifier configuration used to implement a wideband 10 MHz distribution amplifier.
Joe
From: "Charles P. Steinmetz" <charles_steinm...@lavabit.com>
To: Discussion of precise time and frequency measurement
<time-nuts@febo.com>
Date: 03/27/2012 07:28 PM
Subject: Re: [time-nuts] Distribution amp - Use a video amp unit ?
Sent by: time-nuts-boun...@febo.com
Bruce wrote:
>The above reverse isolation [~35 dB] is about 25dB lower than I would
expect.
D'oh! Bruce is right -- I calculated the reverse isolation
incorrectly. I had only been expecting 40 dB, so I didn't question
the result. The breadboard actually measured nearly 63 dB.
>Stable operation at unity gain is necessary if a feedback capacitor is
used.
The Miller capacitance of the output transistors sees to that (with
an even greater phase margin when a faster transistor is used for Q1).
>An LM329 has similar noise without the dissipation of the internal
>heater in the LM399
I know. I just particularly like the 399, and have a pile of
them. I rationalize using it in this case by noting that the range
of frequencies where phase noise of the DA is important includes sub-
to low-Hz frequencies at which thermal effects could make the
unheated 329 significantly noisier (though if you keep drafts off
both of them, it might not be by a large amount).
Best regards,
Charles
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