Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

On Sat, Jan 28, 2017 at 5:53 PM, Mattia Rizzi wrote: > Have you tried to use clock distribution components like 5PB1108? You could > use that to distribute the LT1711 output to the output stages > *independently*. You could use also 5PB1108 as output stage as well (but >

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Hello David, >200ps of skew is consistent with long traces on board material like standard FR4 because of uneven dielectric constant Can you elaborate it? What do you mean by "long traces"? I saw the PCB done by Anders, the track length is about 10 cm. Using the microstrip formula, even for a

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Ruslan wrote: Have you looked at the design of the HP/Agilent/Keysight E1750A (sine timebase of various standard frequencies)...? According to the specifications on the 5087A/E1750A/E1752A spec sheet, the 1750A is no better WRT phase noise than the 5087A, and the 5087A is distinctly ...

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

On 01/28/2017 06:58 AM, Anders Wallin wrote: Hi all, I've been tinkering with another distribution amplifier design and made some measurements earlier this week. Have you looked at the design of the HP/Agilent/Keysight E1750A (sine timebase of various standard frequencies) and E1752A (PPS)

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

On Sat, 28 Jan 2017 13:58:27 +0200, you wrote: >... > >The picture gallery also shows a pulse distribution amp for 1PPS. It has an >LT1711 comparator feeding an 74AC14 buffer with length-matched traces to >74AC04's at the outputs. So far my length-matching didn't give zero >output-skew between

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Scott wrote: Parasitic capacitance on the inverting terminal from routing and the input capacitance of the opamp itself, adds another pole to your opamp's loopgain, burning phase margin. A small compensation cap across the top leg of your feedback divider, would boost your phase margin.

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Nice project. The gain peaking is more than likely from your high speed opamp. Parasitic capacitance on the inverting terminal from routing and the input capacitance of the opamp itself, adds another pole to your opamps loopgain, burning phase margin. A small compensation cap across the top leg

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Hi The real question is: Do you have an application where < 100 ps matching matters? If so do you need to match both at the amplifier *and* at the ends of the cables? Other than a phased array radar, I can’t think of to many situations where the answer is yes … Put another way, for the

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Hello, >The picture gallery also shows a pulse distribution amp for 1PPS. It has an LT1711 comparator feeding an 74AC14 buffer with length-matched traces to 74AC04's at the outputs. So far my length-matching didn't give zero output-skew between the outputs - I see around 150-200ps skew which I

Re: [time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

anders.e.e.wal...@gmail.com said: > I see around 150-200ps skew which I tried to tune a bit with wires and 0R > resistors - without very much success.. any ideas for improving this - or > just leave it at 200ps skew? I don't have the numbers handy, but that's ballpark of an inch of trace on a

[time-nuts] Distribution amplifier (again!) - now mostly ok but has gain peaking

Hi all, I've been tinkering with another distribution amplifier design and made some measurements earlier this week. The goal is roughly 1:8 fan-out, gain of 0 dB, for good quality (Cs, maser, OCXO) 5 or 10 MHz signals in the range of maybe +0 dBm to +15 dBm - in a 1U form-factor. Earlier I made